Bogus ADSB tracking information from FR24 local station

I am connecting MP to my local ADSB decoded stream (port TCP 30003 of my own FR24 receiver) and the label attached to the planes shown on the real time map is bogus :
- Callsign is most of the time empty and it appears time to time during only one second
- Altitude information is false, giving 3067 m instead of 10058 m (i.e. 33000 feet)

When I connect QGC to the same decoded stream, the callsign and altitude are OK.

Attached are MP, QGC and FR24 maps tracking flight SAS2801 for comparison.

And then what the decoded stream from TCP 30003 looks like...

When the ADSB stream entering MP comes from a Mavlink ADSB receiver, the information is properly shown though...

Start by tracing how Mission Planner consumes the FR24 ADS-B decoded stream on TCP port 30003, then compare its callsign and altitude interpretation with the stream shown in the issue and with QGC. Done means the real-time map consistently displays the correct callsign and altitude for this input, as it already does for a MAVLink ADS-B receiver.

Written by the indexing model from the issue text.