DSP settings lost on Up2Stream Pro V3

Hi, I’m new here in this forum and I’m very excited user of the Up2Stream device :smiley:
My first project with the Up2Stream Pro V3 is building a single box 2-way active speaker. I’m using ACP Workbench and configured a low-pass filter (left channel) for bass/mid speaker and high-pass filter (right channel) for the tweeter. I use an external amplifier (Wondom TAMP 2500) which is currently connected to the headphone output.

Everything is basically working well and sounds good and powerful. But yesterday after playing about 1hour music (Spotify over Wifi), the Up2Stream suddenly stopped playing and a big bang was forwarded to the loudspeakers. It seems that the device rebooted (the White Wifi LED was blinking for some seconds). I was able to reconnect and playing music again. No new Wifi setup was necessary. But the sound was awful.
I immediately stopped playing music and disconnected from power-supply. Then I connected the streamer to my computer and read out the DSP settings with ACP-workbench. All settings were deleted - it looks like a factory reset was performed.

Loosing the DSP settings is an absolute no-go for this project because the tweeter will be damaged when played fullrange because of lost filter settings.

Does anyone know how/why this could happen?

Was it a firmware update?

How can I check this? Are there any logs for this?
Current firmware version on board is V4.6.337862.29. When I connected device the first time (~2 weeks ago), the ACP Workbench updated the firmware automatically (unfortunately I don’t know the version at that time).

It sounds like it should be up to date. I am not seeing any information on when a device firmware was last updated. I am not sure what would cause this. There are others in the forum that may know.