2016 outlander GT Bought used

We can’t for the life of us get the trunk release on the fob to work consistently

yes, we have the main button pushed in on the dash and we just put in new batteries. Also we have tried both fobs the car came with. It only releases and closes the doors half the time. Do we need to push it immediately after unlocking the car? Before? Close? Far? We’ve tried it all and can’t get it to open every time !

any help would be great before we take it in and potentially look silly.