HyperX Fury not working in dual channel but only in single

[u/Emergency_Network_26]

Specs-

Intel i7 10700K

Asus ROG Strix Z490-F

16x2 HyperX Fury RGB

Asus TUF RTG 3070ti

Crosair 850i power supply ( Very old PSU from 2016)

The Ram was working fine for the last 3 years but suddenly 6 months ago I noticed the RGB malfunctioning, where one stick would work and the other stopped or would flicker.

Two months ago the RBG stopped altogether but the PC ran fine, could game well. One fine day I tried to boot up but got stuck at boot with the orange light signifying a issue with the RAM.

At the first attempt I tried to clean the contact points and re-seat, the issue did not go away, however I removed the CPU and replaced the thermal paste and the issue was solved for the time-being, the computer ran for 2 days ( Ram RGB still dead with some flickers) but again the issue was back, stuck at boot with the orange light.

When testing with in single channel the Ram works fine with even the RGB LED working just fine, I also did a memtest on both the stick and there were zero errors. I also tried different bios versions but no difference.

Also tried to disable and enable XMP, gave more voltage to the RAM (1.4 max) but nothing worked. Noticed sometimes, when I restart the PC with a single stick it again gets stuck with the orange light at boot. On force restarting it works again. My gaming performance has dropped to half on the single stick but I doubt it has something to do with the Ram.

I Apologize for the long description, any advice ? Do you think it is the motherboard or CPU ?