Trade Crashes

Our trade system crashes!

We switched our realm from a SkyBlock world (I created in creative and then uploaded) to a Regular world created by the server. We found multiple villages, but the villagers can't trade. The window to trade opens and immediately closes. It's like you open and close it quickly. We have tried to restart the server and nothing helps. I closed the realm and then reopened it.

The SkyBlock version had a single village I created with nearly 40 villagers and no issues. To test the issue, I restored the SkyBlock world and now half the villagers there can't trade! My Regular world only has three villagers and none of them can trade now. After not playing for a few days I got on to try again and got in a few trades. My friends joined and suddenly trading crashed again.

It's constantly resetting back a few seconds and lags a ton. We reset our local network without any results.