Iphone 15 pro max motherboard issues

I have been using apple products since the Iphone 6 and never had any problems. In fact, i have been absolutely impressed with the durability and longevity of the apple products.

I purchased the Iphone 15 pro max and have been upset that the motherboard has died twice. i spent nearly $400 to repair it while visiting Vietnam. The phone seemed to have been working properly after the repair, although the usage was heavily reduced as i began using my iPhone 13 Pro Max as my primary phone. It has been approxamintly 3 months since the motherboard repair and once again, it seems the motherboard died. Has anyone else expericenced motherboard issues? I regret not trading the phone in after the first motherboard repair. What would be the best course of action? Should i trade it in broken or repair it and try to sell it?