I'm on the 2.02 RC3 already. I've just ordered IR Probe. Once I receive it, I hope the problem will be eliminated.
I also realized that the offset changes when I switch the power off and on.
Once I power on and set the offset, I can print with that offset a thousand times and the offset will stay same if the power was not switched off.
While setting the offset, G30 S-1 would return the same number even if I retry for 10 times but after a power-off, the number changes.