Invisible overworld enemies kill players around nether portal

Players on my server are getting attacked by invisible overworld mobs around the nether portal. These mobs are not actually loaded, create no particle effects, and do not show in spectator mode but the enemies will cause the players damage until the "slain by ..." message appears. The death message has been zombies, skeletons, creepers, and spiders. As these don't actually seem to be loaded trying to attack does nothing.

This is NOT related to MC-65040 as both the server and client rendering distances are set to 15. It DOES seem to be related to MC-71606 and MC-71572.

I can provide a world save that easily allows reproduction of the scenario.

Thank you.