In v21.0.3, AWI often shows the error "Server connection lost, trying to reconnect...", which freezes the AWI for a couple of seconds, then in most cases it successfully reconnects.
Release : 21.0.3
This is a defect.
The problem is improved in AWI v21.0.4.
Before this fix, the WebSocket connection was closed and re-opened, every 5 minutes. On every re-connect, the banner 'Connection lost' was shown till the connection was re-opened (at least 5 seconds). This was easily noticeable, also when using the browser accessing the AWI on the local server. With this fix, the behavior was changed in that the WebSocket connection is kept alive for 1h, and the notification is only shown if the re-connect took more than 1 second.
Note that if Websockets are not activated in your network, AWI falls back to long polling and the banner may still appear.
Note that since the later versions of 12.3 and 21.0 and higher the AE and AWI have to be in the same version.
This means that you cannot only upgrade AWI to v21.0.4, also the AE needs to be upgraded so AE and AWI are aligned.