Raiders won't spawn during raid

Put the summary of the bug you're having here

What I expected to happen was...:
I expected illagers which would attack the village.

What actually happened was...:
Despite the raid bar showing 1 illager left I couldn't find him. I was looking in creative and spectator mode for him but he was nowhere.

Steps to Reproduce:
1. Get bad omen effect

2. Go into a village
3. Wait for the raid to start

4. And then (in the first wave at least) there is only 1 illager indicated by the boss bar, but you can't find him anyway

5. after restarting the game (and loading the chunks again) the raid does actually start with 5 illagers indicated in the boss bar

6. I killed their leader and 3 other illagers, so there is still 1 illager left but - again - I cant find him anywhere.

I've been looking for him in both creative and spectator mode but he is nowhere