This is a regression and has been fixed with the 6.5.13.0 release which will be out in the first week of June 2022. If you are on 6.5.12.0, please open a support ticket to get the hotfix.
The problem that you are seeing is because you have provided administrator credentials within 'Apache Sling Authentication Service' in configMgr. Please remove the Anonymous User Name and Anonymous Password. You can also disable the 'Allow Anonymous Access' option and check.