Hours cut & coworker working through breaks

Im a bartender/server hybrid who works the AM shift from 9am-4pm, but I almost never stay past 3pm bc the managers have the closers coming in at 2 to relieve me. The restaurant is super dead between 2-5pm, yet for some reason they have 4 staff members coming in to replace me so early. There’s a couple issues here, 1 is that we tip pool between AM/PM because the AM shift is so prep heavy and my job is to essentially do all the hard work so the PM crew has a seamless shift and has everything they need. But the PM crew is really greedy and chomping at the bit to get me off the clock and out of the tip pool as soon as they can. One of the staff members in particular shows up and works through their unpaid break (we go on our break as soon as we clock in) just to make sure the rest of my prep list gets done as quickly as possible so they can kick me off the clock. It’s starting to really irritate me! Everyone’s shifts got cut so now we’re all panicking and scrambling to pick up shifts and milk the clock as long as possible. I’ve spoken to our managers multiple times about pushing the closers back to 4pm so that I can stay on during the slowest hours rather than having 4 closers on during the slowest hours running up labor. Not to mention, because their in time is so early they all get paid OT almost daily. It’s a win/win for them to push their start time back because they would massively save on labor and I would get at least equal hours to the PM crew :/

The PM crew gets really squirrely with me staying at all passed 3pm when my out time is 4 or sometimes 5 but there’s also never a reason for me to be there since 4 people come in and essentially take over whatever there is left for me to do once they get back from their break. One time they were even telling other members of the crew “do I need to speak to a manager to get her off the clock??” Because I was running around helping one of the servers who got sat 10 tables when the rest of the bar team was just lounging around the bar idly. That day I only stayed until 4:11 helping out other staff and I was scheduled until 5. Has anyone else dealt with anything like this?! I used to be a restaurant manager so the schedule truly makes no sense to me and does not reflect the peak busy times.