Internet Connection Sharing, ICS, stops sharing the connection to internet

Question

Summary:
We are experiencing intermittent issues with ICS (Internet Connection Sharing) and have a hard time figuring out the root cause.
The setup is as follows:

1. The PC (Host) is connected to a RNDIS device (Device) via USB cable
2. The RNDIS Device, when connected creates a network interface #2 on the PC
3. The internet ethernet interface #1 on the Host is shared to the interface #2 created by the Device on the Host

All works as intended where the Device can access both the Host (192.168.137.1) and the internet (8.8.8.8) without any issues.

Now to the problem:
After X-time something happens and the device cannot access the internet any more. It's like the routing gets disabled. The Device can however still reach the host (192.168.137.1). We have made sure to change the SharedAccess service to Automatic and to add the registry setting for EnableRebootPersistConnection and can not see any clear link between ICS stopping and system reboots.

Our prime suspect right now is the service SharedAccess. The reason behind this is because we can simulate the problem by stopping the service. Then we can reach the device but the device can not reach internet. The theory is that the service crashes / stops or is stuck in a faulty state. The problem is that we cant see any events around this in the Windows Event viewer. We suspect that this service is not logged.

Any ideas on how to proceed form there would be highly appreciated.

System information:
Version BuildNumber
------- -----------
10. 0.19042 19042
Some info about the host system (PC)
Installed windows updates:
Source Description HotFixID InstalledBy InstalledOn
------ ----------- -------- ----------- -----------
634-CR-10 Update KB4598299 04.02.2021 00:00:00
634-CR-10 Update KB4562830 19.11.2020 00:00:00
634-CR-10 Security Update KB4570334 18.11.2020 00:00:00
634-CR-10 Security Update KB4580325 10.01.2021 00:00:00
634-CR-10 Update KB4586858 04.02.2021 00:00:00
634-CR-10 Security Update KB4593175 04.02.2021 00:00:00
634-CR-10 Security Update KB4598481 10.01.2021 00:00:00
634-CR-10 Security Update KB4598242 10.01.2021 00:00:00
Current Workaround :
To “restart” the ICS and get things running again we have to do the following steps.
• Remove the ICS for the Device
• Add the ICS for the Device again
This restores functionality back to normal

Frequency of the problem:
We have this solution running on ca 100 PC’s since beginning of October this year, all having the same configuration. ICS have failed on ca 70% out of the 100, and after the setup failure, (whitch mostly happens within a week, sometimes two weeks, and sometimes within a few days), the ICS is removed and configured again. Only a few have failed a second time.