motherboard b650

hi there, im looking to get an idea or some suggestions in which motherboards to invest the most because my brother and i we are looking to upgrade both our systems to something more newer "future proof" like. at the moment we both have rtx 4070, ryzen 5600x, and a gigabyte bm550 aorus elite...

I upgraded to a new mobo and gpu a couple months ago, and it has caused persistent, intermittent instability issues I havn't been able to find the cause for. The system will crash seemingly at random, but always while under load, while gaming. The system stops responding, the fans and LEDs...