So this is very weird - in the Epic tab uninstalled games keep showing up as installed when I use the Group by Installed option. Also: games that I started downloading in the Epic client but stopped and cancelled before they were fully installed.

Here's the thing: if I use the Filter option and filter by status, everything displays correctly. Same with the Installed tab - it shows all the truly installed games across all platforms. So for some reason, the Filter tool appears to have the correct info, but the Grouping tool does not.

Deleting the residual folders for the uninstalled games in the Epic install folder didn't seem to help.

Leaving this here for anyone to come across, The only way I managed to get it to show the right Installed games is to "Disconnect" your Epic account from integration settings, then reconnect.

This is still an issue.
It's very annoying, please fix it! :)