Same problem.
Got K95 and for weeks could not figure out why my PC would just hard shut down. Replaced PSU with a 1k watt platinum full-modular PSU thinking it was going out and I still had the issue. Finally decided to uninstall ICUE and PC ran for a week solid without any faults. For testing, I reinstalled ICUE and it hard shut down, once again, within an hour.
No idea how software could cause a hard shutdown without a BSOD. A bit ridiculous if you ask me. $200 keyboard and I can't utilize it's features because the software kills my PC. Not ok and has been an issue for over 6 months.....
There also seems to be a known issue about this on Reddit: