I had to disable Volume Management Device in bios (a relative of Rapid Storage Tech, I think) to get any amount of battery life on an 13th gen Asus Zenbook. Learned it from bugzilla.kernel.org/show_bug.cgi?id=211879.
Look at “cat /sys/kernel/debug/pmc_core/package_cstate_show” (need root to even peek into the debug dir). If you only have C1 and C2 and everything else is zero, then you’re getting no S0ix joy. When things are working correctly, you should get some of the higher states, and a pile of C10 states when you close the laptop.