Omen of Resurgence not proccing at low life

https://imgur.com/a/OwXmxE6
https://imgur.com/a/XmVIKLD (on this one my life is already above threshold because i have gone back to town and life regen is kicking in)

Omen didnt trigger although i was clearly on low life and also had omen activated (see picture) . checked. have it all on a replay video. happy to share if you care and need to see. quite a big let down for hardcore player this is not working - unless i made a huge mistake but wouldnt know how and why. i beleive to have a lost a charcter because of this yesterday ...