I have a 2019 GLC 63 and I was unable to drive my truck for two weeks. So I had to actually jump start it when I got back home. However my lift gate now will not open automatically. It was working fine up until this point. I found a video that said that it may need to get recoded and wanted to know if anyone else has had this problem and if so what is the fix. I fear if I take it to the dealership they are going to try to say I need a new motor and over charge me. If anyone have any information or any solutions I appreciated it.

Are you sure it wasn't a blown fuse from the jump start?

This may help you, I had my 2008 GL420 stood for a while prior to selling it, a couple of days before the guy was coming to look at it I took it for a run and also found the tailgate did not operate correctly.
I thought it may be a low battery issue so charged the battery and all seemed well.
That was before christmas and the guy ( he is a friend ) has not had any issues since.
This leads me to think the lowish battery may have caused it, not sure how, but all ok now anyway.

Could it be caused by a bad aux as well?

not sure, in the GL the aux battery is very tiny and not easy to get at. In the 6 years I had the GL I did not change the batteries at all.

I see.

OP, do you hear the mechanism unlocking at all, did you try manually lifting it if it was unlocked?

OP, did you try checking if you accidentally hit the valet switch in the glove box?

You may get better advice in the GLC AMG section.

Perhaps OP should ask a moderator to move the thread over.