Problems with Telecom Sercomm Fiber router

We have ascertained that the Sercomm telecom router, AGCOMBO model has quite serious problems for the correct functioning of the UCloud and On premises remote applications. The details taken from a problem device are as follows (not exhaustive):

Name of device AGCOMBO
DSL version A2pv6F039u.d26a
Firmware version AGSOT_1.0.4 / AGSOT_1.0.7 / AGSOT_1.0.8 / AGSOT_1.0.9
Bootloader Version 1.04.0
Hardware Type & Version V01

The phenomenon found is the following: if the data flow from the phones arrives at the router while it is restarting, this puts the NAT in crisis and this, probably starting before the other services of the router, already creates sessions which, however, are no longer managed by the software and therefore remain hanging indefinitely. This causes anomalies in the registration of the telephones in the network, especially if only the router is switched off.

It also seems that after connecting a terminal (telephone or gateway) you need to restart the router at least once in your life, otherwise you risk having problems with one-way audio.

Therefore in case of problems the following is required:

• turn off all phones and gateways and stop the PBX if it is local to the network and not Cloud
• restart the router and wait a reasonable time (typically a couple of minutes)
• switch on the telephones and gateways and eventually the PBX if local

Obviously it is also necessary to contact Telecom to try to be fixed (even with a firmware update) or to replace the router.