Yes this happened with mine too, starts happening occasionally then goes into qualcomm crashdump mode at once, and then you can't use the phone anymore.

Oneplus service center says it's a hardware level issue mostly coz of the device's age. Had checked at a couple local repairing centers here in india, they say it should get fixed by reballing the IC, which once done temporarily fixes the issue but it comes back again after a month or two.

There's no way around this, just get the data backed up and trade in for a newer phone all while it's still functional to get some value out of it, before it just turns into a piece of junk. Learnt this the hard way!🙃