random power throttling PL2 making my cpu to run very slow (10w TDP)

I have been owning thsi XPS 13 7390 with i7-10710u for a month now

and I've done repasting thermal grease and undervolting the cpu with Throttlestop.

CPU performs very good for everyday use.

However, whenever I play games (with e-gpu gtx1080ti) or run benchmark, the cpu get power limit throttling PL2 and make my cpu to become 10W TDP with like 1.4ghz clock speed....this is very annoying and I have no clue to stop happening this.

It occurs every a minute or so and comes back to full clock speed after 10 seconds of throttling.

Temperature has always been good so that's not the issue.

Hopefully Dell releases new bios or drivers to fix this.

Or am I missing the solution for this? Any help please?

Thank you