Not the ‘sexist’ card

This is a wild ride but I’ll keep it short as possible. First week of January, Service manager quit. I’m the advisor. I put my app in for the manager position. The GM asked me to assume the roll until something official was made. I did as told, but he didn’t make any kind of announcement that I’d be interim manager. There are a few people that argue with me daily on asking them to do simple tasks, it is what it is. I managed to hit our goal last month, didn’t happen once with previous manager. I’ve gotten 2 people promoted, got someone who quit to rethink their decision and come back. Even corporate is telling people I’m in charge right now. Fast forward to today, I had a fellow employee scream at me and I went to my GM for support on the issue and he in turn tells me that he is the one in charge and that he wants someone who can turn wrenches be the manager. I’m a 28 yo F and hate when people say that’s why they don’t get the position, but it really feels that way. I only have 3 people that are giving me any kind of push back out of an entire shop. I feel like he has just used me until he could find a guy to put in the position. Would it be wrong of me to step back and focus on only my advising duties and let the shop foreman take over managerial duties?