I believe some games require a mandatory update even when installed with Tinfoil while bypassing firmware requirement. I suggest you update to firmware 6.0.1 at least, for now.
If you're using ReiNX, stay away from firmware 6.1 in the meantime.
I'm a ReiNX user myself, but on firmware 6.0.1. So, the breaking bug at 6.1 does not bother me.
Right now, I think your best option for free CFW is either Atmosphere or RajNX, if your Switch's firmware is on 6.1.