Sorry, I didn't know that libdvbv5 was included with LE, being in /usr/bin I think means it is in the baseline. In any case I am happy to see that you found 1.24.1 since you can try other tests. Plus it includes a PR I submitted that was causing scans to fail here in North America.
The syntax for the full mux capture is below You will need to find a host for the 200MB ts files that get created.
dvbv5-zap -c /storage/.kodi/userdata/addon_data/service.nextpvr/config/adapter0-frontend1-DVB-T-channels.conf Prima\ Max -P -t 60 -o fullmux.ts
You can use any channel name in the mux. It might be good to try CT 2 HD T2 as well. If it is easier any channel on those frequencies will do and you don't need to worry about the space. I don't think my demodulator supports DVB-T2 so I am not sure I can try the channel change issue but sub might be able to check that when he looks into the EPG issue.
You would need restart the NextPVR service if it has opened the tuner.
The other test you can do is backup /storage/.kodi/addons/service.nextpvr/nextpvr-bin/DeviceHost/arm32/libdvbv5.so.0 and copy in the new version from 1.24.1 that you found. It won't help with the EPG but it might help the tuning issue.
The Kodi log does not have debug logging before the dvb_fe_set_parms failed stopped playback so I can't see the skip information.