Vinegar smell from HVAC

With everything going on my car has been sitting in an underground garage (73 ambient) and connected to a level 2 charger. I noticed a faint vinegar smell on “cold start” with no preconditioning the other day and was wondering what’s going on. It only lasts a few seconds and then dissipates. When running outside in the 80s / 90s for a couple hours the A/C fan does kick on while charging in the garage.

Any ideas what's going on?

Could just be mold/mildew from A/C system. Easy fix, just spray something like Lysol in cabin air intake, usually clears it up. My cars will do this sometimes and to try and prevent it I will sometimes (when I remember) turn off the a/c a minute or two before I get home so the system can dry out before you shut the car off.

https://www.youtube.com/watch?v=3uAjkr_SuME

Have you checked cabin air filter? It may need to be replaced.

Yeah this is the first time I have noticed it in any car. The cabin filter is probably almost 2 years old. I'll look into the other. Thank you!