Tvheadend

Use temporary Kodi as TVH client to solve problem.

error 405 in your log = bad api communication.

Found a possible workaround - it seems that the SourceID settings is pretty good described in the tvheadend manual:
http://docs.tvheadend.org/webui/config_networks/

SAT>IP Source Number : This field is matched through the “src” parameter asked from the SAT>IP client. Usually (and
by default) this value is 1. For satellite tuners, this value determines the satellite source (dish). By specification
position 1 = DiseqC AA, 2 = DiseqC AB, 3 = DiseqC BA, 4 = DiseqC BB, but any numbers may be used - depends on the
SAT>IP client. Note that if you use same number for multiple networks, the first matched network containing the mux
with requested parameters will win (also for unknown mux). If this field is set to zero, the network cannot be used
by the SAT>IP server.

Somehow - when setting both Networks (DVB-C and DVB-S) to SourceID "1" both start working (without any error messages).
But nevertheless it seems bugged when e.g. setting DVB-S to "1" and DVB-C to "2" (which number to use when DVB-S contains
all of the DiseqC zones ?).

So bug in TVH configuration, with not check itself for duplicating values.

Not really - configuration was correct - it seems with invalid configuration
e.g. sourceids 1 and 1 (instead of the correct sourceids 1 and 2 ) it works as
it is intended with correct configuration.

So yes - there seems to be a bug - or at a minimum a documentation lack regarding
the usage of sourceid with different tuner types.

Perhaps, there's just a misunderstanding what 'src' parameter means in SAT>IP. For DVB-C and DVB-T this value must be 1 (because only one input source is available usually - no cable / antenna switch or so). For satellite, this value means the diseqc position which is defined on the server. So, it's extra information for the tuning. The source IDs should be unique only for the same tuner type.

Ok - thanks for your input Jaroslav - so it seems my "workaround" seems to be the intended usage ^^.
So I think we're done here - no bug at all now :)

Could you please add this note to the Help pages (DVB Inputs - Networks)?

For DVB-C and DVB-T this value must be 1 (because only one input source is available usually - no cable / antenna switch or so).

Now the Help reads:

SAT>IP source number : The SAT>IP source number.

I think it would be useful for example:

SAT>IP source number : The SAT>IP source number. (For DVB-C and DVB-T this value should be set to 1)

So if mixed tuners (SAT + DVB-T ) are used people (like me :) ) would remember to set this value to 1 for DVB-T (and not for example 5 when the previous networks are 1,2,3,4 from a diseqc switch).

Thanks