This notion of losing the dressing room, in the sense that players are so fed up with a particular manager that they actively try to lose matches just to get him sacked, is massively overstated. It happens very rarely, only under extreme circumstances.
With all that competitive spirit flowing through their veins during a match, do you think players will actually worry about how the outcome will impact their manager's future at the club? Their own personal prides are at stake in that moment, who cares about what's happening to a guy on the sidelines? In the worst case, they'll keep giving their best on the pitch while simultaneously hating his guts. That may or may not be enough to get results, but that's a totally different story.
Players having specific reservations about manager's methods, which is far short of losing the dressing room by the way, is probably more common in football than we realize. There's no reason to think that Ange is immune to that. But I don't see any evidence indicating that players are actively sabotaging the team, or the manager.