Siri has no audio in CarPlay through AutoKit dongle

My car's infotainment system is Android-based so I had to buy a medium (AutoKit) to be able to run CarPlay on it.

However, since a couple of OS updates, Siri's voice stopped working: the media plays fine (with a couple of seconds delayed) but whenever I try calling Siri or attempt to have Siri read my received messages (iMessages, SMS, WhatsApp, etc.), there is no audio output.

I tried rebooting the system, uninstalling/reinstalling AutoKit software, unpairing/repairing CarPlay connection, attempting to reroute the audio output, and other attempts to fix it with no luck...

I tried asking around shops but they all said they're unable to fix or overwrite the infotainment system's OS; only selling a different dongle in hopes of repairing it (and even that is not guaranteed). YouTube didn't have any working solutions so far but I haven't looked much into it