89% at 42 cycles does seem low.
It isn’t anything you are doing. You don’t need to discharge the battery, or use fruit juice, or coconut oil, or any of the other gimmicky apps or shamanic rituals.
I would take/send it in and let them reassure you, or fix it.
My M1 MBP I bought Jan 2021 has 161 cycles, and 87% capacity.
Technologies have changed and this is not the case anymore. Yet those bad memories of NiCd batteries and their memories still persist.