Ok thanks.
As I said it is multiple different containers tried in combination with the same result each time. I’ve tried 3 different VPN containers combined with 2 different Bittorrent containers and am getting the same result each time, but only on Dietpi. They work each time on an X86 VM. In all cases, there is no bittorrent connectivity.
I can share the qbittorrent logs but they’re from inside the container; but essentially the connections keep timing out and there are no specific errors that I can find. As you say that’s probably more relevant to the container maker (s). But the common denominator as fas as I can see currently is docker on dietpi.
In terms of the bug I mentioned; this is it on the tracker and it has been open since 2019: DietPi-Software | Docker: Inter-container bridge broken by VPN · Issue #2863 · MichaIng/DietPi · GitHub Maybe it’s been fixed and never closed but as I said it’s the only thing I could find that seemed relevant.
I’ve been thinking about it today and I’m going to try making a custom docker bridge network (rather than rely on the automated set up), and if that doesn’t work then try the same stack with Raspbian OS and a fresh DietPi image on SD cards. I’m just curious to find the cause. 