I wish there was a Max trial (while on Pro) to test if this was the case or not. Even if it was just a 24 hour trial. Max is an expensive trigger to pull, and hope it just solves this.
FWIW I went Claude Max after Pro, and the trick is to turn off Opus. If you do that you can pretty much use Sonnet all working day in a normal session. I don't personally find Opus that useful, and it burns through quota at 5x the speed of Sonnet.