Files shared with Anyone sometimes prompt users to request acccess to the file

Are the share links only to direct files or to folders usually, do you know by chance? Usually the only reason you would get request access is because you are authenticated and something on the screen is rendering that it isn't liking. There used to be a bug on Guest Teams sharepoint sites where you would get Access request after the screen loaded because it was trying to render photos that the guest account couldn't read from somewhere else in the tenant.

But because it's random it makes it rather odd. Usually first time is because your not authenticated and SSO kicks in then try again and it works. Hence why there might be something odd requiring authentication of the page to happen.

I guess one thing to check, when it works check the name in the top right, is it anonymous when it does, and the users name when it gives access requests? Or vice versa? might be something to keep an eye out for to give some clues.