Does the FTM 500 have RX Front End Issues?

Does the Yaesu FTM 500 have front end issues? Ive seen 2 radios now where the Receive Signal gets worse and worse in a fast space of time. I done a video on it using a Signal Generator. Today I have seen another FTM 500 loss 5 S points of signal on the meter. Same fault.

Does the FTM500 have a crap front end? Is it a common fault?
Heres my video of the test: https://www.youtube.com/shorts/7mpj9JZuSGc

Anyone else have the same issue?