Permission denied on key "net.ipv4.conf.all.src_valid_mark"

[yesimanoob]

Hello! Thank you for taking the time to read this report. As shown in the title, I'm having permission error setting the sysctl to get wireguard working properly.

I've read the FAQ and, to the best of my knowledge, applied the appropriate settings (privileged=true, net.ipv4.conf.all.src_valid_mark=1) but I am still getting that permissions error.

FWIW, I am running this via Portainer on OpenMediaVault (OMV) 5.6.13, which is Debian 10 based, using the Proxmox PVE testing kernel (5.11.22).

Attached are the necessary debug log and docker settings files:
supervisord.log dockerinspect.txt

[yesimanoob]

I tried spinning up the delugevpn docker with wireguard enabled and it worked fine the first try, so it seems to me that my host is okay.

Here are the debug logs and docker settings for the deluge try.
supervisord-deluge.log
dockerinspect-deluge.txt

I can't tell what's going on between the two, but this stands out in the rutorrent logs:

2021-08-17 17:21:17,368 DEBG fd 11 closed, stopped monitoring <POutputDispatcher at 140312270548128 for <Subprocess at 140312270547456 with name pyrocore-script in state RUNNING> (stdout)>
2021-08-17 17:21:17,368 DEBG fd 15 closed, stopped monitoring <POutputDispatcher at 140312270006112 for <Subprocess at 140312270547456 with name pyrocore-script in state RUNNING> (stderr)>
2021-08-17 17:21:17,368 INFO exited: pyrocore-script (exit status 0; expected)
2021-08-17 17:21:17,369 DEBG received SIGCHLD indicating a child quit
2021-08-17 17:21:32,473 DEBG 'start-script' stdout output:

I tried running a clean rutorrentvpn docker initially configured to run with wireguard, and its logs showed it dying right after the same loglines, but they occurred earlier in the startup routine.

I have no idea what these are but there is nothing similar in the delugevpn logs so this looks like an indication towards what's wrong.

Any help would be greatly appreciated!