This problem may be a plugin or theme conflict. Please attempt to deactivate all plugins and switch to the default Twenty Twenty-Two theme. If the problem goes away, re-activate them one by one to identify the source of the problem.
If you can install plugins, install Health Check. On the troubleshooting tab, you can click the button to deactivate all plugins and change the theme for you while you’re still logged in without affecting normal visitors to your site.
Blank admin pages after a core update is very likely related to cached JS files. This has become an issue as WordPress has moved to JS-based functionality (the blocks editor). So, clear any caching you may have (I need to purge Cloudflare and Varnish), and try in an incognito/private tab.
Normally if this is JS/cache related you can also check by looking at the dev console. You’ll see a whole bunch of JS errors there.
It’s very annoying. I have over 200 sites on a network and cannot purge all the domains after a core update as the server would get hammered.