Keychain Access not opening / Passwords not working, when accessing Mac remotely

I have a new Mac which I have been using for some weeks, that I setup to sync on iCloud with a new Apple Account. However, for the last few days, Passwords app has stopped working. It is empty and I cannot add any new passwords. When I try to add a password, nothing happens, it is not saved. I also tried opening Keychain Access app, but it asks for my login password and then just does nothing, it does not open. Any suggestions on how I can get things working again? I have latest macOS version at the time of writing. **Update:** I should have mentioned that this happens when I am accessing the Mac in question remotely, using Apple's solutions (Screen Sharing, or Remote Desktop). This seems to be a crucial aspect, because now that I am sitting locally in front of the Mac, and I open Passwords, everything works fine. So, could this be an issue with Remote Desktop access only?