diff --git a/frontend/src/app/components/blockchain-blocks/blockchain-blocks.component.html b/frontend/src/app/components/blockchain-blocks/blockchain-blocks.component.html
index 17c5709fd..400016d02 100644
--- a/frontend/src/app/components/blockchain-blocks/blockchain-blocks.component.html
+++ b/frontend/src/app/components/blockchain-blocks/blockchain-blocks.component.html
@@ -14,20 +14,26 @@
             }}</a>
         </div>
         <div class="block-body">
-          <div [attr.data-cy]="'bitcoin-block-offset=' + offset + '-index-' + i + '-fees'" class="fees">
+          <div *ngIf="block?.extras; else emptyfees" [attr.data-cy]="'bitcoin-block-offset=' + offset + '-index-' + i + '-fees'" class="fees">
             ~{{ block?.extras?.medianFee | number:feeRounding }} <ng-container
               i18n="shared.sat-vbyte|sat/vB">sat/vB</ng-container>
           </div>
+          <ng-template #emptyfees>
+            <div [attr.data-cy]="'bitcoin-block-offset=' + offset + '-index-' + i + '-fees'" class="fees">
+              &nbsp;
+            </div>
+          </ng-template>
           <div [attr.data-cy]="'bitcoin-block-' + offset + '-index-' + i + '-fee-span'" class="fee-span"
-            *ngIf="block?.extras?.feeRange">
+            *ngIf="block?.extras?.feeRange; else emptyfeespan">
             {{ block?.extras?.feeRange?.[1] | number:feeRounding }} - {{
             block?.extras?.feeRange[block?.extras?.feeRange?.length - 1] | number:feeRounding }} <ng-container
               i18n="shared.sat-vbyte|sat/vB">sat/vB</ng-container>
           </div>
-          <div [attr.data-cy]="'bitcoin-block-' + offset + '-index-' + i + '-fee-span'" class="fee-span"
-            *ngIf="!block?.extras?.feeRange">
-            &nbsp;
-          </div>
+          <ng-template #emptyfeespan>
+            <div [attr.data-cy]="'bitcoin-block-offset=' + offset + '-index-' + i + '-fees'" class="fee-span">
+              &nbsp;
+            </div>
+          </ng-template>
           <div [attr.data-cy]="'bitcoin-block-' + offset + '-index-' + i + '-total-fees'" *ngIf="showMiningInfo"
             class="block-size">
             <app-amount [satoshis]="block.extras?.totalFees ?? 0" digitsInfo="1.2-3" [noFiat]="true"></app-amount>
diff --git a/frontend/src/app/components/hashrates-chart-pools/hashrate-chart-pools.component.ts b/frontend/src/app/components/hashrates-chart-pools/hashrate-chart-pools.component.ts
index ed3683e9b..df7780fee 100644
--- a/frontend/src/app/components/hashrates-chart-pools/hashrate-chart-pools.component.ts
+++ b/frontend/src/app/components/hashrates-chart-pools/hashrate-chart-pools.component.ts
@@ -5,7 +5,7 @@ import { delay, map, retryWhen, share, startWith, switchMap, tap } from 'rxjs/op
 import { ApiService } from '../../services/api.service';
 import { SeoService } from '../../services/seo.service';
 import { UntypedFormBuilder, UntypedFormGroup } from '@angular/forms';
-import { poolsColor } from '../../app.constants';
+import { chartColors, poolsColor } from '../../app.constants';
 import { StorageService } from '../../services/storage.service';
 import { MiningService } from '../../services/mining.service';
 import { download } from '../../shared/graphs.utils';
@@ -173,6 +173,7 @@ export class HashrateChartPoolsComponent implements OnInit {
     this.chartOptions = {
       title: title,
       animation: false,
+      color: chartColors,
       grid: {
         right: this.right,
         left: this.left,
diff --git a/production/nginx-cache-warmer b/production/nginx-cache-warmer
index 27d1e3a8f..db025a137 100755
--- a/production/nginx-cache-warmer
+++ b/production/nginx-cache-warmer
@@ -120,14 +120,16 @@ do for url in / \
 
 	do
 		warm "https://${hostname}${url}"
+		sleep 0.25 # wait 250ms between queries to not DoS mariadb
 	done
 
 	for slug in $slugs
 	do
 		warm "https://${hostname}/api/v1/mining/pool/${slug}"
+		sleep 0.25 # wait 250ms between queries to not DoS mariadb
 		warm "https://${hostname}/api/v1/mining/pool/${slug}/hashrate"
+		sleep 0.25 # wait 250ms between queries to not DoS mariadb
 		warm "https://${hostname}/api/v1/mining/pool/${slug}/blocks"
+		sleep 0.25 # wait 250ms between queries to not DoS mariadb
 	done
-
-	sleep 10
 done