Skype wants to access my login keychain, and won't take no for an answer
The issue is that every month or more, the Skype app for macOS will ask for keychain access. The only way to make it shut up is to enter my password and click the Always Allow button, then do this again a second time.
Checking the Keychain appears to yield a little information that may be helpful. Skype stores two unique keychain items, therefore it needs to be granted permission twice. Examining the two keychain items for their passwords appears to indicate that they're storing JSON blobs with base64 encoded security tokens, and also storing a Unix timestamp as an expiration time for these tokens. After the token expires, it appears that rather than rewriting the password to the new credential tokens, they simply delete the two keychain items and recreate them from scratch the next time they refresh the tokens. New tokens, new authorization all over again.
I'd bug Microsoft's Skype team about this, but they probably know how their own app works. Couldn't find a category in the support tags for third party software. Thought this information would be useful anyway.
Mac mini, macOS 12.1