Roav SmarCharge Car Kit F2 firmware update not taking

HI – I have two of these car chargers / bluetooth-FM transmitter devices.
I’ve tried to update the firmware (when prompted) a half dozen times with two different android phones.
One (moto x4) fails instantly – the pixel xl2 goes through with the ~4 minute procedure but when the device reboots, I am prompted to upgrade the firmware again, so it doesn’t seem to be taking.

I’ve done a lot of searching and haven’t seen this reported, but I know the app was just updated (it wouldn’t even load before this update on my main phone).

I guess I’ll email support as well.