@TheGingerDog swap RAM modules? Run memtest from USB?
@TheGingerDog also tempting to run with case off, see if overheat? After that, if passes, likely software/driver. Try Wayland vs X11 ?
@falken well, memory test was happy .... I've given it a good clean with an air duster ..... I guess I just need to wait and see if it behaves better.
@falken I ran memtesr86+ on it when I added more ram to it ages ago ... But I probably stopped it after 15-20 mins when no errors were reported ... I suppose it would make sense to run it (to completion) again. Thanks for the hint !