THC not getting active even when "all seemingly needed" requirements are met

Its an odd looking voltage plot.
I would look at the time after arc ok the THC is activated. To me it looks like it needs to be 2 seconds. I just can't see the setting I'm looking for.
Early activation could be disabled by the big fluctuations in voltage.

ok, found this to try those 2 seconds maybe:

Two methods of THC activation are available and are selected with the Auto Activation check-button. Both methods begin their calculations when the current velocity of the torch matches the cut feed rate specified for the selected material:

Delay Activation (the default) is selected when Auto Activation is unchecked. This method uses a time delay set with the Delay parameter.

Auto Activation is selected when Auto Activation is checked. This method determines that the arc voltage is stable by using the Sample Counts and Sample Threshold parameters.

Hello all, this is an update for my issue.

While trying to debug the THC activation happened that the voltage readings started to get erratic i.e. -39v until it completely failed. At some point identified that the encoder differential input chip was super-hot. I assume it got damaged by some EMI spike. had that chip replaced at a laptop shop, I only tried it again with a new NON HF plasma source, the new plasma is not CNC, only some relay interface used for starting and. THC is working now. so bottom line, in my case the HF plasma was causing too much trouble. Thanks all for your ideas and hope this if useful for someone in the future.

Antonio.