Sup /p/

Just recently I was out shooting downtown with a Sony a7 and a Tamron 28-75. I switched to my 50mm for a little bit, then back to the 28-75 and noticed it wouldn't allow me to change the f-stop. All of my other lenses work fine, and when I don't allow the camera shutter to open without a lens on it, it won't shoot with the 28-75. Is this an issue with my lens? Is it fucked? Is there anything I can do?

Bumping with random photos.

Thanks in advance for any advice, /p/