diff --git a/backend/src/api/bitcoin/bitcoin-api.ts b/backend/src/api/bitcoin/bitcoin-api.ts
index e4557b65f..97a428c23 100644
--- a/backend/src/api/bitcoin/bitcoin-api.ts
+++ b/backend/src/api/bitcoin/bitcoin-api.ts
@@ -41,7 +41,9 @@ class BitcoinApi implements AbstractBitcoinApi {
 
   $getBlockHeightTip(): Promise<number> {
     return this.bitcoindClient.getChainTips()
-      .then((result: IBitcoinApi.ChainTips[]) => result[0].height);
+      .then((result: IBitcoinApi.ChainTips[]) => {
+        return result.find(tip => tip.status === 'active')!.height;
+      });
   }
 
   $getTxIdsForBlock(hash: string): Promise<string[]> {
diff --git a/backend/src/api/blocks.ts b/backend/src/api/blocks.ts
index 79b11bcb1..40687060f 100644
--- a/backend/src/api/blocks.ts
+++ b/backend/src/api/blocks.ts
@@ -252,7 +252,7 @@ class Blocks {
     const blockHeightTip = await bitcoinApi.$getBlockHeightTip();
 
     if (this.blocks.length === 0) {
-      this.currentBlockHeight = blockHeightTip - config.MEMPOOL.INITIAL_BLOCKS_AMOUNT;
+      this.currentBlockHeight = Math.max(blockHeightTip - config.MEMPOOL.INITIAL_BLOCKS_AMOUNT, -1);
     } else {
       this.currentBlockHeight = this.blocks[this.blocks.length - 1].height;
     }
@@ -271,17 +271,19 @@ class Blocks {
         this.lastDifficultyAdjustmentTime = block.timestamp;
         this.currentDifficulty = block.difficulty;
 
-        const previousPeriodBlockHash = await bitcoinApi.$getBlockHash(blockHeightTip - heightDiff - 2016);
-        const previousPeriodBlock = await bitcoinApi.$getBlock(previousPeriodBlockHash);
-        this.previousDifficultyRetarget = (block.difficulty - previousPeriodBlock.difficulty) / previousPeriodBlock.difficulty * 100;
-        logger.debug(`Initial difficulty adjustment data set.`);
+        if (blockHeightTip >= 2016) {
+          const previousPeriodBlockHash = await bitcoinApi.$getBlockHash(blockHeightTip - heightDiff - 2016);
+          const previousPeriodBlock = await bitcoinApi.$getBlock(previousPeriodBlockHash);
+          this.previousDifficultyRetarget = (block.difficulty - previousPeriodBlock.difficulty) / previousPeriodBlock.difficulty * 100;
+          logger.debug(`Initial difficulty adjustment data set.`);
+        }
       } else {
         logger.debug(`Blockchain headers (${blockchainInfo.headers}) and blocks (${blockchainInfo.blocks}) not in sync. Waiting...`);
       }
     }
 
     while (this.currentBlockHeight < blockHeightTip) {
-      if (this.currentBlockHeight === 0) {
+      if (this.currentBlockHeight < blockHeightTip - config.MEMPOOL.INITIAL_BLOCKS_AMOUNT) {
         this.currentBlockHeight = blockHeightTip;
       } else {
         this.currentBlockHeight++;
diff --git a/backend/src/routes.ts b/backend/src/routes.ts
index 8ccc9c2e1..710cd8378 100644
--- a/backend/src/routes.ts
+++ b/backend/src/routes.ts
@@ -681,7 +681,7 @@ class Routes {
       }
 
       let nextHash = startFromHash;
-      for (let i = 0; i < 10; i++) {
+      for (let i = 0; i < 10 && nextHash; i++) {
         const localBlock = blocks.getBlocks().find((b) => b.id === nextHash);
         if (localBlock) {
           returnBlocks.push(localBlock);
diff --git a/frontend/src/app/components/block/block.component.ts b/frontend/src/app/components/block/block.component.ts
index 4e7b08373..512b6b411 100644
--- a/frontend/src/app/components/block/block.component.ts
+++ b/frontend/src/app/components/block/block.component.ts
@@ -217,12 +217,8 @@ export class BlockComponent implements OnInit, OnDestroy {
       this.blockSubsidy = 0;
       return;
     }
-    this.blockSubsidy = 50;
-    let halvenings = Math.floor(this.block.height / 210000);
-    while (halvenings > 0) {
-      this.blockSubsidy = this.blockSubsidy / 2;
-      halvenings--;
-    }
+    const halvings = Math.floor(this.block.height / 210000);
+    this.blockSubsidy = 50 * 2 ** -halvings;
   }
 
   pageChange(page: number, target: HTMLElement) {
diff --git a/frontend/src/app/components/blockchain-blocks/blockchain-blocks.component.ts b/frontend/src/app/components/blockchain-blocks/blockchain-blocks.component.ts
index 7a0123a78..4352944c6 100644
--- a/frontend/src/app/components/blockchain-blocks/blockchain-blocks.component.ts
+++ b/frontend/src/app/components/blockchain-blocks/blockchain-blocks.component.ts
@@ -110,7 +110,7 @@ export class BlockchainBlocksComponent implements OnInit, OnDestroy {
     this.markBlockSubscription = this.stateService.markBlock$
       .subscribe((state) => {
         this.markHeight = undefined;
-        if (state.blockHeight) {
+        if (state.blockHeight !== undefined) {
           this.markHeight = state.blockHeight;
         }
         this.moveArrowToPosition(false);
@@ -127,7 +127,7 @@ export class BlockchainBlocksComponent implements OnInit, OnDestroy {
   }
 
   moveArrowToPosition(animate: boolean, newBlockFromLeft = false) {
-    if (!this.markHeight) {
+    if (this.markHeight === undefined) {
       this.arrowVisible = false;
       return;
     }
diff --git a/frontend/src/app/components/latest-blocks/latest-blocks.component.ts b/frontend/src/app/components/latest-blocks/latest-blocks.component.ts
index cef512388..5bdb55ece 100644
--- a/frontend/src/app/components/latest-blocks/latest-blocks.component.ts
+++ b/frontend/src/app/components/latest-blocks/latest-blocks.component.ts
@@ -109,8 +109,12 @@ export class LatestBlocksComponent implements OnInit, OnDestroy {
     if (this.isLoading) {
       return;
     }
+    const height = this.blocks[this.blocks.length - 1].height - 1;
+    if (height < 0) {
+      return;
+    }
     this.isLoading = true;
-    this.electrsApiService.listBlocks$(this.blocks[this.blocks.length - 1].height - 1)
+    this.electrsApiService.listBlocks$(height)
       .subscribe((blocks) => {
         this.blocks = this.blocks.concat(blocks);
         this.isLoading = false;
diff --git a/frontend/src/app/dashboard/dashboard.component.ts b/frontend/src/app/dashboard/dashboard.component.ts
index 33fb5ea91..610f45765 100644
--- a/frontend/src/app/dashboard/dashboard.component.ts
+++ b/frontend/src/app/dashboard/dashboard.component.ts
@@ -144,6 +144,9 @@ export class DashboardComponent implements OnInit {
           this.latestBlockHeight = block.height;
         }),
         scan((acc, [block]) => {
+          if (acc.find((b) => b.height == block.height)) {
+            return acc;
+          }
           acc.unshift(block);
           acc = acc.slice(0, 6);
           return acc;
@@ -153,6 +156,9 @@ export class DashboardComponent implements OnInit {
     this.transactions$ = this.stateService.transactions$
       .pipe(
         scan((acc, tx) => {
+          if (acc.find((t) => t.txid == tx.txid)) {
+            return acc;
+          }
           acc.unshift(tx);
           acc = acc.slice(0, 6);
           return acc;
diff --git a/frontend/src/app/services/state.service.ts b/frontend/src/app/services/state.service.ts
index 98a65d34a..5e181063b 100644
--- a/frontend/src/app/services/state.service.ts
+++ b/frontend/src/app/services/state.service.ts
@@ -71,7 +71,7 @@ export class StateService {
   network = '';
   blockVSize: number;
   env: Env;
-  latestBlockHeight = 0;
+  latestBlockHeight = -1;
 
   networkChanged$ = new ReplaySubject<string>(1);
   blocks$: ReplaySubject<[BlockExtended, boolean]>;
diff --git a/frontend/src/app/services/websocket.service.ts b/frontend/src/app/services/websocket.service.ts
index ae4c0e381..1eb9a56e6 100644
--- a/frontend/src/app/services/websocket.service.ts
+++ b/frontend/src/app/services/websocket.service.ts
@@ -68,7 +68,7 @@ export class WebsocketService {
         clearTimeout(this.onlineCheckTimeout);
         clearTimeout(this.onlineCheckTimeoutTwo);
 
-        this.stateService.latestBlockHeight = 0;
+        this.stateService.latestBlockHeight = -1;
 
         this.websocketSubject.complete();
         this.subscription.unsubscribe();