Tvheadend

Hi All

This is my first post here, so please be gentle.
I'm new to TVH but I guess I can call myself an FFMEPEG expert - anyway...
What I need is the possibility to change URLs of Muxes.
I know that there are ways to do so. One example suggesting this works is for instance here: https://github.com/lcapriotti/watchWilmaa

I totally fail in calling any script from any mux.

As a kind of simple example:

1. Having a mux configured with
URL: "pipe:///usr/bin/ffmpeg -i https://mcdn.daserste.de/daserste/de/master.m3u8 -c:v copy -c:a copy -strict experimental -metadata service_provider=IPTV -metadata service_name=Sendername_ohne_Leerzeichen -f mpegts pipe:1"
perfectly fine delivers me the livestream of "das erste".

2. Putting this same thing in an sh file does not work.

2a. I created an sh file called DasErste.sh and put it in /home/hts/.hts/.
DasErste.sh looks like this:
"
#!/bin/bash

ffmpeg -i https://mcdn.daserste.de/daserste/de/master.m3u8 -c:v copy -c:a copy -strict experimental -metadata service_provider=IPTV -metadata service_name=Sendername_ohne_Leerzeichen -f mpegts pipe:1
"

2b. As URL for the mux I think I need to use: pipe:///home/hts/.hts/DasErste.sh I tried this (and probably more than 300 slightly changed calls) without success.
It results in a scan failure. Result is TID:65536 and scan result is fail. Checking "Ignore TSID" does not help. Placing the SH file in other directories does not help either.

Can anyone share an example of how to call an SH script from a MUX ?

Thank you in advance,

Tobi

PS: I'd love to share TVH logs but i can't find them - if you let me know where these are stored I'm of course happy to share...