Unable to update WordPress version

Hi,

My site is telling me an update is available and it wants me to update to WordPress 5.8.1 (we are currently running 5.2.12), but when I follow the update link I get an error message:

Cheatin’ uh? Sorry, you are not allowed to access this site.

I am confused because its my site and im logged in so I dont understand why I wouldnt be allowed access??

Is anyone able to help me understand whats going on here and help me fix it??

Thanks