This Question Mark means the internal connectivity test fails and instead of a network icon, there is a question mark. Apparently, there are no network issues, but that question mark is annoying.
If you don’t need it, you can turn it off.
Method 1)
Go to Settings > Privacy > Connectivity Checking
Set it OFF. (Then, restart your WiFi connection)
Method 2)
Add a file in /etc/NetworkManager/conf.d for example 20-connectivity.conf with the following content. (You might want to check if you have other conf file with that options or if you added something in /etc/NetworkManager/NetworkManager.conf)
[connectivity] uri=
The empty uri disables this test.
That's all it takes to disable it.
