Hi @Bernard Emmanuel,
Thank you for posting in this community.
I tested it on my side but didn't have your problem.
However, we can work together to narrow down and resolve the situation. So, please kindly provide more information below to let us work further.
1.You can add a people web part in page or add a person column in a list to see whether you can search SharePoint groups. Make sure the SharePoint group you want to use is a Microsoft 365 group or a security group. These are the only types of groups that are supported for audience targeting. You can check the type of group in the Microsoft 365 admin center or the Azure Active Directory portal.


2.Are other users with same permissions facing the same problem? View through another computer or account.
3.Whether all SharePoint pages have the same problem? You could create a new page to check.
4.Whether all SharePoint libraries have the same problem? You could create a new library to check.
5.Check if the same issue occurs with other SharePoint site collections.
6.You could try to clear browser cache then restart it.
7.Try to use a different browser or your browser's InPrivate mode to see if the same error occurs.
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