Is it a bad heavy karma to criticize or give up your guru? "However it is said in the Guhyasamaja Root Tantra:"

"If sentient beings commit an action 
As grave as the five heinous crimes 
He [still] can attain the superior Vajra Vehicle, 
But who from within disregards his master 
Shall never attain, even if exerted."

"That means having given up your guru, criticized the guru, or having heresy or broken samaya with one’s guru. It is not possible to explain how heavy the negative karma is from these things. One who criticizes, hurts, or belittles one’s guru from the heart will not achieve anything in this life; even if one practices one won’t achieve anything."

https://www.lamayeshe.com/advice/killing-ones-parents

Does asking a sceptical question count as criticism? Such as why the guru is charging x-amount for teachings? And giving up a bad guru is it bad? Does it matter if the guru is buddhist or not? Perhaps this only applies to certain types of buddhism?
Heavy bad kamma is always a matter of strong wrong view, and ingratitude is such especially if it's toward real and lasting help: Toward one's Gods, Parents, people of goodness.

Much done.

It's how ever not bad if based on right view and if the relation is a more or lesser good trade with the world, it would be even good to seek for leaving, correct of course and not just for another similar way.

[Not given for trade, exchange, stacks and what ever relations not dedicated toward real liberation]