Upgrade error with AirVantage Platform

Hello,
I set up and activated the firmware update on AirVantage Platform, of my HL8548 modem to v5.5.26 which is the latest version available.
After a few minutes, my modem restarted by itself.
Since then it transmits requests like +SIM:1 or +SIM:0 if I remove the SIM card, but does not answer any AT questions.
How can I get the modem working again ?

Thank you for your help.

how about flash the FW locally by exe file?

Yes, but rather Linux method because “exe” is windows method.

but is it normal for the AirVantage platform not to work ?
This is a big problem when the modem is on an operating site.

i think it should work for AVMS

What is AVMS?
Thank you for your help

just short form of airvantage management

YOU: just short form of airvantage management
ME: Can you describe it to me or give me a link to understand the short form of airvantage management ?

YOU: how about flash the FW locally by exe file ?
ME: Yes, but rather Linux method because “exe” is windows method.

Can you answer these two questions ?

you can see here:
https://doc.airvantage.net/av/

normally for linux, we use xmodem file, but currently your modem is not responding AT command, you need to route the USB to windows