First time I ran the benchmark in Shadow of the Tomb Raider after installation on my MBP 14" M1 Pro I got 13 fps on high at 1080p. I thought my Mac was faulty. The second time I got 45 fps as it should be. I got similar result in Metro Exodus so I do believe it's something about running the game for the first time. Rosetta kicks in the first time you start an app and I suspect that the app itself is compiled but there may be other assets that are not directly compiled before they're used? I'm not sure but that was my experience with the games the first time.
I ran it again, its actually worse than I though. The game seems to be locked at 30fps now, no matter what settings I choose. There are also people complaining about the same thing on twitter. Disappointing. I have requested a refund for now.