No improvement I'm afraid. But the fact that the "Muxes awaiting initial scan" stops at 5 is probably related to the last 5 log messages that mention "Front configuration failed -- Invalid argument, frequency: 140733195449032". I don't know if it is relevant, but I'm using a duo lnb from CanalDigitaal (Netherlands). I created one extra satellite config entry. Both are set to "Universal" LNB type, one for switchport 0, the other for port 1. But my guess is only one is correctly working as I only Astra 23.5 yields multiple muxes, Astra 19.2 only one.
This is the log from the console (the output in the browser is not different from earlier):
whiskey@Mythbox:~/tvheadend-build/andoma-tvheadend-9075408/build.Linux$ ./tvheadend -C[WARNING]:accesscontrol: Created default wide open access controle entry
[INFO]:dvb: Found adapter /dev/dvb/adapter0 (STB0899 Multistandard) via PCI
[INFO]:dvr: Creating new configuration ''
[WARNING]:dvr: Output directory for video recording is not yet configured for DVR configuration "". Defaulting to to "/home/whiskey/Videos". This can be changed from the web user interface.
[INFO]:CSA: Using SSE2 128bit parallel descrambling
[NOTICE]:START: HTS Tvheadend version 2.12.99 started, running as PID:5146 UID:1000 GID:1000, settings located in '/home/whiskey/.hts/tvheadend'
[INFO]:AVAHI: Service 'Tvheadend' successfully established.
[NOTICE]:dvb: Adapter "STB0899 Multistandard" mux autodiscovery set to: On
[NOTICE]:dvb: New mux "12,551,500 kHz Vertical (No satconf)" created by built-in configuration from "Astra-19.2E"
[NOTICE]:dvb: New mux "10,758,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "10,788,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "10,802,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "10,842,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "10,862,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "11,475,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "11,515,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "11,675,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "11,739,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "11,798,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "11,836,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "11,875,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "11,914,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "11,992,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,012,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,070,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,168,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,525,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,525,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,565,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,565,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,630,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,631,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,636,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,641,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,644,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,649,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,661,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,685,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,696,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,711,000 kHz Horizontal (No satconf)" created by built-in configuration from "Astra-23.5E"
[NOTICE]:dvb: New mux "12,725,000 kHz Vertical (No satconf)" created by built-in configuration from "Astra-23.5E"
[ERROR]:dvb: "/dev/dvb/adapter0" tuning to "12,636,000 kHz Vertical (No satconf)" -- Front configuration failed -- Invalid argument, frequency: 140733195424032
[ERROR]:dvb: "/dev/dvb/adapter0" tuning to "12,641,000 kHz Horizontal (No satconf)" -- Front configuration failed -- Invalid argument, frequency: 140733195429032
[ERROR]:dvb: "/dev/dvb/adapter0" tuning to "12,644,000 kHz Horizontal (No satconf)" -- Front configuration failed -- Invalid argument, frequency: 140733195432032
[ERROR]:dvb: "/dev/dvb/adapter0" tuning to "12,661,000 kHz Horizontal (No satconf)" -- Front configuration failed -- Invalid argument, frequency: 140733195449032
[ERROR]:dvb: "/dev/dvb/adapter0" tuning to "12,696,000 kHz Horizontal (No satconf)" -- Front configuration failed -- Invalid argument, frequency: 140733195484032
Please let me know if there is anything else I can try and thanks for the help.