I had this same problem before, but couldn't manage to solve it and ended up ditching the modpack. In short, after a few minutes of play, the game crashes. I can still "play" but every block I brake doesn't drop, when I'm wearing an elytra I keep flying even when I'm on the ground, I can't go to other dimensions, and so on, as if the minecraft ticks stopped. Once you try to close minecraft it crashes completely and when you start the world again you spawn the point just before this issue started appearing. Rn I'm playing with "better minecraft plus" v22 to which I added optifine and easy villagers. Mind you that Yesterday worked properly, so I doubt that the mod compatibility is an issue. Any ideas?