I have mounted a route between two points in my network between headquarters and store. The route is ok, and the shop DrayTek is responding to ping normally. It happens that with time, it just stops responding.

I enter the route configuration, and give an OK without changing anything in the IP configuration, return it to respond normally. Because DrayTek 1 is losing communication with DrayTek 2? Because only "renew" build it back to answer normally?

I've given the boot in both devices, the behavior follows the same.

Could someone help?