Even though you mentioned not finding it, the usual path for the Teams cache on Windows 11 x64 is %appdata%\Microsoft\Teams. Inside this folder, the most relevant subfolders for the cache are Cache, blob_storage, databases, GPUCache, IndexedDB, Local Storage, and tmp. If you can't locate these, it might indicate an unusual issue with your Teams installation or user profile. Regardless, since the problem persists across other platforms (web, mobile), it's less likely to be a local cache issue.
To try clearing the cache again:
Completely close Teams. Make sure it's not running in the background (check your system tray icons).
Open File Explorer.
Type %appdata%\Microsoft\Teams into the address bar and press Enter.
See if the mentioned folders are present. If they are, try deleting them (or moving them to a backup folder for safety).