Is your SoundSend puck is flashing red? This means it is actively trying to connect to a specific Lithe Audio speaker that it previously saved, but that speaker has vanished from the network.
Open the SoundSend App, go to Advanced Settings, and select Channel Check.
Look at the graphical layout to see which speaker is missing. Walk over to that physical speaker:
Check that it hasn't lost power (verify if its LED is completely off).
If the speaker's LED is blinking green, it dropped out of WiSA mode. Give the Pro Series reset button a 1-second tap (or press PAIR on the back of the iO1) until it chimes and the purple LED returns.
Go back to the SoundSend App and tap Scan for Speakers
to restore the network.
If it continues blinking red, perform a factory reset via the app on the puck and start a fresh scan.