Audi s4 2001

Didnt drive for 2 weeks while on vacation and battery died so I replaced with a new one.

A few days later when i parked for the night and turned my car off, all the windows rolled down on their own. Rolled them up and everything was fine.

Next day after driving, the alarm started to go off at random intervals when i was away from my car. When i would turn the alarm off, the lights on the inside would flicker on and off. Also, some times the car would lock/unlock just fine, other times it seemed to be completely unresponsive (previous owner didtn give me keyless, so this was all done manually).

Any ideas on what may be the problem? This never occurred before i left on holiday so I dont think it would be a broken hatch sensor or anything.