Account connection is sensitive; temporary disconnection happens sometimes. There could be issues at the broker's side, on the network or proxies, at the server's side, or at our side; many factors are involved, and we cannot guarantee a 100% sync permanently. Nonetheless, we are trying to minimize the consequences in such situations. For example, broker demo accounts usually have a lower service level, and disconnections may happen more regularly due to the broker.

If your account is disconnected, please follow these steps:
Verify the credentials and login details (server name and broker). If your broker is not yet supported, we can easily add it. Just contact us on our Live Chat
Instead of copy-pasting your credentials, we encourage you to manually type them to avoid copying and pasting bad characters.
Make sure that there is no blank space.
Be sure the account is an MT4 or MT5.
Be sure to select the broker server from the list in the dropdown. Just start writing your broker's name and select it in the list.
You can try to log out and log in from the MT4/MT5 to verify the login details.
Or you can try to reset the password.
Verify also that you have assigned a subscription to your Slave/Follower.
You can try to switch OFF/ON the account too.
If you have a paid plan, you can try to change the server location in the global settings at the top right in order to reset the connection.
It may take a few minutes for an account to reconnect, so be patient.
We are permanently working to have the most stable and accurate Trade Copier; however, many factors and third parties are involved, and there are things out of our control as server, proxies, network, or brokers' issues that may happen. By changing the server location, it would reset the connection, and it may help.
Also, we can recommend that you activate email (free) alerts for your master and slave accounts. Alerts are sent in case of disconnection or when an order fails to copy.