@hamishbm -- I solved this by reverting to a prior fw release:
sudo rpi-update 86b202d127ca3d413d0779d870cce2169afaacd7
Zero issues since. JFYI
@hamishbm -- I solved this by reverting to a prior fw release:
sudo rpi-update 86b202d127ca3d4 13d0779d870cce2 169afaacd7
Zero issues since. JFYI