Plaato Airlock needs a stable local 2.4 GHz WiFi-network to operate.
If your WiFi signal strength is poor, connection issues might arise.
Remove any obstacle close to your Airlock, that might be getting in the way of the connection from the WiFi router.
Place the fermenter closer to the WiFi-router
If there are many bluetooth devices in the same room, trying moving away from them.
Install a WiFi-repeater if the range is not sufficient
Try using a different USB-charger
Change the channel on which the router is operating on