I just tested this in a 20.04 install, and the daily live image.
CTRL+T opens a new tab in Firefox and Dolphin (in X session) just fine.
Sounds like you have something additional interfering with the key assignment.
I just tested this in a 20.04 install, and the daily live image.
CTRL+T opens a new tab in Firefox and Dolphin (in X session) just fine.
Sounds like you have something additional interfering with the key assignment.