Lift gate problem on a 2018 Highlander.

What is your question?

Often my lift gate will stop working and it is very hard to get it closed. What is causing this?

What makes this problem better or worse?

It seems to happen when the small black button that opens the back window is pushed. It happens every time I have my car washed so I am thinking the men push that button thinking it opens the door.

How long has your 2018 Toyota Highlander had this problem?

Months