NPC Shops

[KingBohica]

Hello,

I'm trying to make a shop owned by an NPC. I am using EssentialsX. I can set-up a shop, and use /qs setowner [npc name] and it accepts the transfer. I can even buy and sell from the shop. The items are transferred and the NPC's balance is correctly changed. However, after a brief time, the shop owner on the sign changes to "Unknown". I also noticed this error in the console:
INFO java.lang.RuntimeException: Economy username cannot be null

Is there a way to fix this? Also, do you have a Discord channel I can join? I didn't see a link to it anywhere. Thanks for your help!