ubuntu 18.04 suspend issue with wowlan enable

Question

There are 3 senarios:

1

launch ubuntu
pm-suspend
wake-up
work

2

launch ubuntu
iw "$PHY" wowlan enable magic-packet disconnect  // enable wake on wifi
pm-suspend
wake-up
freezes

3

launch ubuntu
pm-suspend
wake-up
iw "$PHY" wowlan enable magic-packet disconnect  // enable wake on wifi
pm-suspend
wake-up
work

The diff between #2 and #3 is: if wowlan enable before first pm-suspend, then ubuntu would freezes after resume. if I do a pm-suspend, resume first, and then wowlan enable, the from then on, the pm-suspend/resume work work.

So, I feel that, I need to do a pm-suspend/resume before the first wowlan enable, then ubuntu suspend would work.

While definitely this is a bug, I want it to be fixed from root.