My keyboard finally ‘almost’ working after a clean uninstall of Synapse 4.
It was cycling / resetting every 7 minutes like the USB device was being unplugged/plugged back in. So, following other advice, I Unchecked the boxes that says Allow the computer to turn off this device to save power in DEVICE Manager.
Didn’t work.
But, thought about this: the USB C cables have different functions: Primary is ‘signal and power’ and Secondary is just a ‘pass thru’ cable to attach other USB devices.
So, I tried swapping the cables , that were attached to my motherboard USB ports.
FIXED. NO MORE CYCLING.