Gmod Server Issues/Bugs

Hey guys, for quite some time now, I’ve had this problem when playing in another server.
First of all my “tab” key doesn’t work.
If the server says: (eg. Press F1 to access DeathRun store) or (eg. Press F1 for Menu), When I press F1 to do so, nothing happens. NOTHING.
AND when someone is talking, nothing comes up saying who is talking on mic.
This has been going of for MONTHS now.

Any ideas?