diff --git a/lib/util/http/github.ts b/lib/util/http/github.ts
index a96fad6973222cbde6f187af1997bfb6a1c702e8..69e6718132c51406268e71e70b44880a70ca65e6 100644
--- a/lib/util/http/github.ts
+++ b/lib/util/http/github.ts
@@ -15,7 +15,8 @@ import { regEx } from '../regex';
 import { GotLegacyError } from './legacy';
 import { Http, HttpPostOptions, HttpResponse, InternalHttpOptions } from '.';
 
-let baseUrl = 'https://api.github.com/';
+const githubBaseUrl = 'https://api.github.com/';
+let baseUrl = githubBaseUrl;
 export const setBaseUrl = (url: string): void => {
   baseUrl = url;
 };
@@ -308,7 +309,10 @@ export class GithubHttp extends Http<GithubHttpOptions, GithubHttpOptions> {
     const result: T[] = [];
 
     const { paginate = true } = options;
-    let count = options.count || 100;
+
+    let optimalCount: null | number = null;
+    const initialCount = options.count || 100;
+    let count = initialCount;
     let limit = options.limit || 1000;
     let cursor: string = null;
 
@@ -322,6 +326,8 @@ export class GithubHttp extends Http<GithubHttpOptions, GithubHttpOptions> {
       });
       const fieldData = res?.data?.repository?.[fieldName];
       if (fieldData) {
+        optimalCount = count;
+
         const { nodes = [], edges = [], pageInfo } = fieldData;
         result.push(...nodes);
         result.push(...edges);
@@ -351,6 +357,19 @@ export class GithubHttp extends Http<GithubHttpOptions, GithubHttpOptions> {
       }
     }
 
+    // See: https://github.com/renovatebot/renovate/issues/12703
+    // istanbul ignore if
+    if (
+      optimalCount &&
+      optimalCount < initialCount && // log only shrinked results
+      baseUrl === githubBaseUrl
+    ) {
+      logger.debug(
+        { optimalCount },
+        'Successful GraphQL query with shrinked pagination size'
+      );
+    }
+
     return result;
   }
 }