Regression from 5.7 - suspend not working on XPS

Hardware is Dell XPS L502X (yes - 9 years old and still going strong)

Suspend and hibernate on 5.6.19 on Fedora31 works fine

On upgrade to 5.7.11 or 5.7.14 or 5.8.0 on Fedora 32 it fails:

# cat /sys/power/state
freeze mem disk
# echo mem >/sys/power/state
bash: echo: write error: Device or resource busy
# echo freeze >/sys/power/state
bash: echo: write error: Device or resource busy

Any ideas on how to fix?