Chateau 5G AX unable to renew lease

Hello,

I have the new Chateau 5G Ax, it works very well but I have this problem.
I’am on a Bouygues LTE network, 4G and 5G. Initial connection is ok, the router take its IP from the Bouygues network and all is fine.
But after 24 hours the connection is closed, and apparently it cannot reconnect, I must reboot the device to get a new connection.
I never experimented this behavior with a Huawey router that I used before the Chateau.
I don’t think that’s a DHCP lease renewal problem because the LTE1 states a failed connection.
BTW it’s almost impossible to use the WWW interface to log on the device when in this state; I must use SSH to do a system reboot.
But this problem seems to be linked with my use of Firefox, not quite sure.

The OS revision is 7.10.1 'stable)
modem is a RG502Q-EA with firmware revision RG502QEAAAR13A03M4G

Any idea?
Thanks