The way I see it you have three options.
1. Wait - TX is going to eventually release am update to SXOS that will be compatible with 7.x. Nobody knows when this will be not even the mods but there is official word that it wont take much longer now.
2. Use a different CFW - There are guides to go from SXOS to atmosphere If you either cant wait or want to switch entirely to another inferior Custom Firmware. Here is a guide to something like that
https://gbatemp.net/threads/tutorial-from-sx-os-to-atmosphere.533337/ (if someone wants to link to a guide on these forums please let me know if there is one and I'll remove gbatemp)
3. Downgrade - Here's a link
but be careful because you could potentially brick your switch https://team-xecuter.com/community/...kable-switch-unit-install-6-2-emunand.130467/
I would recommending waiting because its the most risk free out of these options but if you just have to have the cfw then know there are different ways to get there.
Hope that helps.
Edit: Yeah let me make that clear; option 3 is definitely not recommended but for the sake of helping here is pretty much all of your options. What tokyo said.