diff --git a/lib/modules/platform/bitbucket/index.ts b/lib/modules/platform/bitbucket/index.ts
index 195f4a65b4a2c1bf7a40dc2f26c2bf0d94d78c97..9678aa2443b45ec317e5c5963e4b2513cd3fbdfb 100644
--- a/lib/modules/platform/bitbucket/index.ts
+++ b/lib/modules/platform/bitbucket/index.ts
@@ -283,7 +283,7 @@ function matchesState(state: string, desiredState: string): boolean {
 }
 
 export async function getPrList(): Promise<Pr[]> {
-  logger.debug('getPrList()');
+  logger.trace('getPrList()');
   return await BitbucketPrCache.getPrs(
     bitbucketHttp,
     config.repository,
diff --git a/lib/modules/platform/bitbucket/pr-cache.spec.ts b/lib/modules/platform/bitbucket/pr-cache.spec.ts
index ef71374fb292c48216f31dd2efc7d6bed9c75713..ac16cc38a228ea06e22ea8e2e3a7b0195ce4f20d 100644
--- a/lib/modules/platform/bitbucket/pr-cache.spec.ts
+++ b/lib/modules/platform/bitbucket/pr-cache.spec.ts
@@ -89,6 +89,55 @@ describe('modules/platform/bitbucket/pr-cache', () => {
     });
   });
 
+  it('resets cache for not matching authors', async () => {
+    cache.platform = {
+      bitbucket: {
+        pullRequestsCache: {
+          items: {
+            '1': prInfo(pr1),
+          },
+          author: 'some-other-author',
+          updated_on: '2020-01-01T00:00:00.000Z',
+        },
+      },
+    };
+
+    httpMock
+      .scope('https://api.bitbucket.org')
+      .get(`/2.0/repositories/some-workspace/some-repo/pullrequests`)
+      .query(true)
+      .reply(200, {
+        values: [pr1],
+      });
+
+    const res = await BitbucketPrCache.getPrs(
+      http,
+      'some-workspace/some-repo',
+      'some-author',
+    );
+
+    expect(res).toMatchObject([
+      {
+        number: 1,
+        title: 'title',
+      },
+    ]);
+    expect(cache).toEqual({
+      httpCache: {},
+      platform: {
+        bitbucket: {
+          pullRequestsCache: {
+            author: 'some-author',
+            items: {
+              '1': prInfo(pr1),
+            },
+            updated_on: '2020-01-01T00:00:00.000Z',
+          },
+        },
+      },
+    });
+  });
+
   it('syncs cache', async () => {
     cache.platform = {
       bitbucket: {
diff --git a/lib/modules/platform/bitbucket/pr-cache.ts b/lib/modules/platform/bitbucket/pr-cache.ts
index 06b9b4f33fc078abc381890ed0d50db0d2dc6da3..a270f45b6aa9ccb7dd98216d876c9afeffd9cd1a 100644
--- a/lib/modules/platform/bitbucket/pr-cache.ts
+++ b/lib/modules/platform/bitbucket/pr-cache.ts
@@ -3,6 +3,7 @@ import { DateTime } from 'luxon';
 import { logger } from '../../../logger';
 import * as memCache from '../../../util/cache/memory';
 import { getCache } from '../../../util/cache/repository';
+import { clone } from '../../../util/clone';
 import type { BitbucketHttp } from '../../../util/http/bitbucket';
 import { repoCacheProvider } from '../../../util/http/cache/repository-http-cache-provider';
 import type { Pr } from '../types';
@@ -23,7 +24,15 @@ export class BitbucketPrCache {
     let pullRequestCache = repoCache.platform.bitbucket.pullRequestsCache as
       | BitbucketPrCacheData
       | undefined;
-    if (!pullRequestCache || pullRequestCache.author !== author) {
+    if (!pullRequestCache) {
+      logger.debug('Initializing new PR cache at repository cache');
+      pullRequestCache = {
+        items: {},
+        updated_on: null,
+        author,
+      };
+    } else if (pullRequestCache.author !== author) {
+      logger.debug('Resetting PR cache because authors do not match');
       pullRequestCache = {
         items: {},
         updated_on: null,
@@ -66,6 +75,7 @@ export class BitbucketPrCache {
   }
 
   private addPr(pr: Pr): void {
+    logger.debug(`Adding PR #${pr.number} to the PR cache`);
     this.cache.items[pr.number] = pr;
   }
 
@@ -135,7 +145,22 @@ export class BitbucketPrCache {
       cacheProvider: repoCacheProvider,
     };
     const res = await http.getJson<PagedResult<PrResponse>>(url, opts);
-    this.reconcile(res.body.values);
+
+    const items = res.body.values;
+    logger.debug(`Fetched ${items.length} PRs to sync with cache`);
+    const oldCache = clone(this.cache.items);
+
+    this.reconcile(items);
+
+    logger.debug(`Total PRs cached: ${Object.values(this.cache.items).length}`);
+    logger.trace(
+      {
+        items,
+        oldCache,
+        newCache: this.cache.items,
+      },
+      `PR cache sync finished`,
+    );
     return this;
   }
 }