For some days now we've experienced issues with the TPS dropping below 4 or 5. It's even been crashing from time to time.

So far I've noticed it only happens when entering one area of the world. This tells me it's a chunk error somehow. I've then removed the chunks and regenerated them, but the problem is still there. Our timings report show something about villagers which I have no clue about what is. It's correct there are some villagers in the area, but not more than maybe 5-8.

When leaving the area and waiting for about 5-10 minutes, the TPS is back at about 19.9.

Timings report: https://timings.spigotmc.org/?url=soyamudodo

What to do?