Hello,
A few months ago, I purchased a K55 off of Amazon to replace my 10 yr old keyboard.
Ever since getting the K55, just the fact that it is plugged into my computer causes issues. Several software and games will stall for a long time and then crash and lock up my whole computer.
Software I have problems with (let me know if listing these is a no-no):
Retroarch
MAME
Other video game emulators.
The keyboard has been determined to be the root of the issue. Unplugging the keyboard resolves all these issues, which isn't the best option for playing many games in a row. Doesn't matter if ICUE is open or not, lights on or off, etc.
Plugging into a USB3 port seems to fix it, but that is hit or miss.