Force200/180 4.4.1 in NAT mode and pppoe blocks traffic to LAN

Hello people, we have a problem with some Subscriber Modules randomly stops passing traffic to LAN. We actually know to have this problem since firmware 3.5.1. Last known firmware without this problem was 3.2.2. Now with 4.4.1 problem continues to appear and we have some very angry customers. 

What happens is that the Subsriber module doen't forward traffic to LAN while all devices in LAN respond normaly to simple ping. In the same time port forwarding is not working even on Separate Wireless Management IP Address. The subsciber module itself has still access to internet and resolves any dns address. 

The only solution to solve this problem is to reboot the subscriber module, then everything goes back to normal. 

I was able to capture the following with tcpdump:

https://pastebin.com/RJeVB9Qv

If someone from cambium needs, I also got the tech support file while the problem occured.

Hi,

Thanks for the information. Having tech support during the issue happens can help. Can you please open up support ticket and mention me in it?

Thanks,

Dmitry