I just noticed an update to the Lumin app (12.1.9) that “improves network resubscription.”
My educated guess is that this update enhances the app’s ability to re‑establish its control connection to LUMIN hardware after brief network interruptions.
Similar to how Roon endpoints periodically re‑announce themselves on the network, the LUMIN app now performs a more robust resubscription to the device’s UPnP/streaming services when iOS backgrounding, Wi‑Fi transitions, or short discovery gaps occur.
I imagine the result is quicker recovery of the control path, more consistent device visibility, and fewer cases where the app needs to be relaunched to regain communication with the player.
Anyway, that’s my supposition!