Laptop hangs. Sometimes comes back. Other times a poweroff/reboot is necessary

I have a Dell 7506 I7 11th gen laptop. I upgraded to win11 in May '26. Since then, this problem has continually gotten worse. I don't know this is a windows problem for sure. I replaced the fan and put new thermal paste on the CPU and GPU, and the problem still occurs. My SSD died in Feb '26 and I put in a lower grade Intel one. I mention that because the last system events always seemed to be hard disk related. All the diagnostics I have run on the SSD say it is fine. I even tried to clean up any corrupted files. I have a couple of event viewer files from the last two problems, but I cannot attach them here. I'm getting tired of chasing loose ends to no avail. I am much more of a hardware person than software. I have not tried going back to Win10 yet. Any good suggestions on how to proceed to the fastest solution?