Definitely not normal.
I’ve got mine for 2 years now and could probably still count crashes like that on one hand. so if you are sure it’s not a faulty sd card or something like that causing this i’d send it back.
e: sometime ago an Update introduced Fan Curve settings, its a checkbox in the system settings titled “enable updated fan control”, some people reported higher temps with that enabled, so your crash might be the system powering down to avoid overheating, thats atleast worth a try.
Nikon itself offers an F-Mount to Z-Mount adapter which should retain autofocus and stuff like that on many lenses. the adapter is named FTZ Adapter. The z mount is nikons mount system for their mirrorless cameras.
So do some reading to find out if your lenses will work with it and the camera you are interested in and then decide if you like the lense enough to invest in the adapter and a compatible body.