Sharepoint site permissions issues - Visitors group users not granted access

Hey there,

One of our colleague was wrongly given the "owner" role for a SP site. That person went to the advanced permissions settings panel and randomly deleted the site default "Visitors" group.

Then of course every persons depending on that permissions level to visite the site received a "Denied access" error when trying to reach the site.

What we saw was

• no more "visitors" group in the advanced permissions settings panel BUT;

• "visitors" group still appearing in the basic consol on the website (gear icon>site permissions) and enclosing users;

• when checking access to specific pages or content "visitors" group was missing.

We then recreated a new "Visitors" group with "read only" classic permissions. Yet same issue "Denied access" and same observations made (see bullets list above).

We did it again creating a very similar group called "Read-only". After several trials. we asked permissions to access the page directly from the error page "Denied access". User was then able to access the site.

From there we checked the permissions status for that user, from that check we can see that this user is depending on the "Visitors" and "Read-only" groups...

Yet we can't see that user withing these groups... Of course if we deleted the user from all users and add it in one of these two groups, it can't access the site.

We read a lot on permissions lately but can't find anyone else experiencing this.

Additional info:

• This site is part of a hub and is the only one affected

• All sites are configured the same way

• The only settings that changes was that deleted default "visitors" group on that specific website. (so it has to come from that)

• We won't be asking people to ask for permissions from the "Denied access" error page since it would not solve the original issue and we set up groups within Active Directory to easily manage users and their permissions across MS apps.

Should anyone have a solution ;)...

Cheers