As you have tried all software versions I guess you are using the classic hardware.
Is your box ( classic hardware) duff: not necessarily
The aircraft on the map, what is their distance to your station? If they more than 100nm by 150nm away, it would be very uncommon for a deaf box. Also the quite high count of received airframes indicates, that the box is ok.
If you have had many aircraft on the map on day 1 and only 2 on day two and the maximum reception range has reduced to a few nautical miles. Further the total count of received airframes has reduced significantly reduced. Than the possibilty, that box went deaf is very high.
If this isn't the case, here are some other possibilties:
You have two airframes on the map. How many aircraft have a small globe on left side next to the status column? The count should be more or less equal to the number of aircraft on the map. If there is a huge difference there might be an issue with the software interface for grafic content. If that is the case I've no idea how to fix it.
Not all aircraft are equipped with ADS-B. But only ADS-B equipped airframes will show up on the map. Usually all new commercial airframes ( Boeing, Airbus, in less count Bombardier, Embraer) are equipped with ADS-B transmitters.
My station for example:
Late evening, early morning: 90% ADS-B aircraft
Daytima average work day: 70% ADS-B aircraft
Holidays/weekend an great weather: 50% and less ADS-B aircraft due to many small aircraft only equipped with mode s transponders
If able, please attach a screenshot of your myflights list.
Regards Ingo