PC Version
9 out of 10 times, this fix by WombiiActual will correct what you described in your original post of not being able to see other aircraft. Specifically, there is a known issue with the C172.
The link to the fix is about 4 posts down, but it will explain what EVERYONE since SU9 has had to overcome.
NOTE: Someone might have already suggested this “Now Required” fix by a 3rd party to fix MSFS, but this thread has become out of control and I didn’t read past the first few replys.