WiFi SSID Information
Since Android 11, thanks to Google, my apps can no longer access WiFi SSID information when in background.
This means that within the apps, more specifically in network manager, you will find your currently connected network WiFi SSID, however it might not show in widgets or other notifications, but instead it will show "no permissions".
You will likely see a “unknown ssid” most of the time in widgets. Other WiFi information are just fine. It’s because SSID is considered to give away your position and thus requires localization permission which is now restricted in background (and Google refused that my apps receive it in background, even though actual localization is never used).
If rooted, you can install 3C Helper (in app's settings, active tweaks) so that it will access WiFi SSID again to be displayed in widgets just as before.
Without root, I'm sorry to report there is no way to get WiFI SSID (none that I know of at this time).
You can get more details about this on those pages: