GPD Win Max 2 2023 not stable above 6400 MT/s. should I be worried?

Need advice folks. I have a 2 week old GPD win max 2. i’ve just finished running 3 memtests on 6400, 700 and 7500 repsectively from a memtest boot disk. unit only passed on 6400 MT/s. should I claim warranty on this or leave it as is?

I was having trouble with two games, MGSV and Monster Hunter Rise, they would keep crashing windows consistently after 5 mins of playtime. Temps, TDP are normal. (other games work fine)

After switching back to 6400MT/s only did these two run for a solid 30 mins.

Is the inability to run stably at 7000 or 7500 MT/s enough to claim warranty?