F- devices filter out Mode S planes without Callsign, and don't contribute MLAT

[CRJ08]

Hellos, it's been years feeding, and I have devices from FA and FR24, and the FR24 doesn't show all aircraft on the list, I've done some test and found out that the problem is that F- devices, those sent by FR24 itself, don't help with MLAT because they're filter out a lot of planes, I'm venezuelan, most planes here are not ADS-B, only Mode S, so I know what I'm talking about, all B732, B734, B733, E190, Citations, Commanders, etc etc etc, all those planes are received and displayed by FA receiver, and are received by FR24 receiver, you can see on the decoder status, you can see total aircraft 10, ADS-B 3, and MLAT 2, and on the a/c list will appear only 5 aircraft, other 5 won't be sent to the site/servers/web, I use a VRS and can see what each receiver is getting at the same time, FR24 almost always filter out this mode s planes, sometimes they appear but for just a moment, then they disappear, even when they are in coverage, obviously when they appear on the list, they appear on the site, mlat, but that's like 5% of the time. It's not working properly, I made a test, using the FA receiver, installed the FR24 Pi software, connected, as a t- receiver, so connected and checked ports, port 30002 shows all the planes, years before you could see those planes at 30334 port, now you can't check that port, I repeat F- devices don't contribute to MLAT unless planes are sending Callsign, T- devices work fine, western Venezuela has help from Colombia and Curacao and there are more T- devices over there than what they are here in eastern Venezuela, support says there's nothing wrong, but, yes. There's something not working properly. Sorry if this is not the correct topic. Please, check you receivers and you can see what I'm saying, thanks.