LM1300 LTE modem stops routing traffic between the WAN and LAN ports after 6 hours approximately

I have setup my LM1300 between my broadband connection and my Netgear Orbi Pro router to serve as a failover when the broadband connection is unavailable  However the LM1300 stops routing traffic from the WAN port after 6 hours.  The broadband connection is still available but the LM1300 does not route traffic. All 4 lights are green on the modem.  It also does not failover to 4G at this point.  When this occurs all internet connectivity is lost.  This has been an issue since purchase (i.e. the modem has never worked properly)

This issue has been reported on this forum in one from or another quite a few times now by a number of users over many months and I have not seen any resolution.  If there is new firmware available to address this problem please indicate where I can download it otherwise please advise on how the problem can be resolved.

I have taken the following steps:

• Checked for firmware updates using the modem settings web page.  The modem initially downloaded a firmware update when I first turned it on but no new updates since then.
• Factory reset the modem. This actually seemed to help for a while.  The modem ran for 2 days after the factory reset without dropping the WAN.  However I triggered a WAN failover as a test to make sure the LTE functionality worked.  The modem switched to LTE as expected and then switched back when I reconnected the WAN.  6 hours later the WAN connection dropped again.  So the factory reset did not fix the issue.

Here are the modem details:

Firmware Version: EC25AFFDR07A09M4G

App Version: NTG9X07C_20.06.09.00

Web App Version: LM1300-HDATA_03.03.103.201

Bootloader Version:

Hardware Version: 1.0

Please advise how this issue can be resolved.  The modem is essentially useless at this point since it requires manual intervention every 6 hours.

Thanks

DM