I have a few questions about the ZOOM modem I own. I bought the DreamPi kit, Line voltage inducers and modem from dreamcastlive several years ago.

I stopped using the kit because I'd moved house and didn't have enough space to install my consoles and play online with my Dreamcast.
Recently, I was able to get a "SEGA gaming" room and reinstalled my system. I installed the latest sofware 1.9 DLE and everything worked.
I encountered recently. During 2 different sessions on PSO, I was disconnected from the server after more than 20 min of play.
Last night, I simply couldn't connect at all, neither to PSO nor any other game, nor the web.
I noticed that none of the 2 green LEDs on my ZOOM modem were lit. After several RESETs, waiting for the Dreamcast modem to be exchanged, apart from a flicker when removing the RJ11 cable or reconnecting the USB modem to the Rasp, nothing. No initialization.
This morning, I rebooted my system without touching anything, and after a few minutes, the 2 LEDs lit up and I was able to connect.
Do you have any idea what's wrong?
Is it my ZOOM modem or something else?
Thanks in advance.