This is repeated until I power off, wait and power the Qbox back on. Simply rebooting is impossible. Equally I cannot rmmod (or modprobe -r) the relevant modules because they are “in use” despite no software on the system accessing them (i.e. tvheadend has been shut down). I do wonder if this is a firmware issue or perhaps a hardware problem – is it some incompatibility with tvheadend (I don’t think so – least I don’t think this is a tvheadend issue)? Whatever the issue it’s pretty annoying that I must power cycle the qbox so regularly.
I didn’t find the right solution from the Internet.