If you could get no .lock, the issue is not the network, it is that some process is having the .lock.
In the easiest case you can cat /var/lock/....log and read the PID (process ID) of the locking process. ps aux | grep [PID] is showing the name.
If the file is empty, you need the workaround over lsof /var/lock/... …
And when we know the process, we can find out how to solve. It doesn’t make sense to put in ideas out of the blue.
In your screenshot is also /var/log/opkg.lock mentioned.
If the file is not there and the update can’t create it, it seems to be a problem with the user(rights).
Not very typical for user root, but my answer is only standard Linux knowledge, I haven’t have this issue on a router myself.
I just tried disabling all startup scripts of plugins I installed, and stopping those.
After that I was able to run opkg update again. I re-enabled all services I disabled & it still works right now. Not sure what caused it, if I fixed it, or if it resolved itself, but it seems to be fixed at the moment🤷♂️