Lighting bolt on fast clock circuit does not convert villagers

The first and last lightning bolts convert villagers to witches while all of the bolts in between don't

Steps to reproduce:
1) Put down a sticky piston with a lightning rod on the face and a channeling-enchanted trident thrown on the rod
2) Activate and deactivate the piston fast and repeatedly
3) Spawn villagers while the piston is moving again and again

Expected results:
Villagers get turned to witches by lightning and get damaged

Actual results:
Villagers remain as villagers and also don't take damage from the lightning.