I've experienced this issue with the Control X4 in a collective with the Control XS. The XS did not fail communication but the X4 did.
I rebooted the collective but no change. Power down/Power up of the X4 was the next step and that fixed the problem.
I've also experienced loss of communication with the WiFi Power Strip in the same manner and it required Power down/Power up. But I've never had the single WiFi plug or the Control XS fail, not even once.
@Carlos
In all instances it does seem to be related to WiFi network stability, as each lockup event was approximately the same time there was thunderstorm activity in my area. However, a complete reboot of the WiFi network does not/did not resolve the problem for me. It required power-down of the Hydros devices.
I've since had to rethink my reliance on Hydros and have now placed a Kasa WiFi Powerstrip ahead of Hydros power modules so that I can remotely reset Hydros devices. Kasa has yet to fail a reconnect to WiFi, even under the worst circumstances like multiple power interruptions, lengthy outages etc.