Solution: give it time. I have been experiencing the same thing where sometimes I don't get a new work unit for a while...I think the servers are just overloaded (which is actually encouraging in terms of the desire/demand from the public to help). It has nothing to do with your router.
ping 188.8.131.52:80 isn't a valid address to ping. Ping doesn't have a port number.
Folding@home servers are crazy busy at the moment trying to supply a 20x increase in number of clients. One of my boxes has been idle for some 5 days or so, but just suddenly started receiving work units today.
Your post has been mentioned in several forums that I am member of. Do you know if you are receiving any work at all? When Sony and the Pande Group stopping developing the Android Folding@Home client then I thought that any of those work queues would eventually empty with no more work available.
I have restarted several non-ARM machines to process Folding@Home WU with the COVID-19 jobs but I don't know if any ARM jobs are being sent out. If there is work available then I know I would like to see what you have done to get the Folding@Home client to work in OpenWrt
Guy Forssman posted above that he had installed Folding@Home on a Dir-860B1 which is an ARM based router. There was an older Android client that was developed by Sony with the Pande Group but Sony stopped developed and the app was pulled from the Google Play Store.
I don't know how Guy has installed Folding@Home on his OpenWRT build but I am interested if he is receiving WU from Folding@Home. The older Android client doesn't show the same information as the desktop client so if Guy is using that as a base then it is not clear if he getting WU or not.
At least in this thread, there is no explicit mention of @Forssux installing folding at home on the router.
The mention is just about what router hardware is in use (for context about any router configuration details). At least as I read it, this does not imply that there is a folding client on the router.
Given the relatively modest compute power of most consumer grade routers (when compared against any basic general purpose desktop/laptop computer, or even a phone), the extremely limited ram and storage, and the need to operate normally as a router without causing bandwidth to suffer, I’d honestly be very surprised if it would even be plausible to run folding on a consumer router at all, or at the very least to complete the work unit in anything resembling a reasonable amount time.
Edit: it is not possible from a work unit deadline perspective. Period. This excerpt from the faqs page should make that clear:
WHAT ARE THE MINIMUM SYSTEM REQUIREMENTS?
All computers can contribute to Folding@home. However, if the computer is too slow (e.g. wasn’t built in the last 5 years or so), the computer might not be fast enough to make the deadlines of typical work units. A Pentium 4 or newer equivalent computer (with SSE) is able to complete work units before they expire.