"websocket error" when trying to login

Hi, i just set up the admin-ui to my project and everything works perfectly fine with my local api (localhost:3000), but if i try to connect to my production api (using PM2 & NgInix) i get the error "Error: websocket error". I'm not sure why it can't connect to my sockets.. i'm using the same hashed password (stored in .env file) 

Any idea what could cause the problem ? @darrachequesne