F4pro V2 can't recognize receiver signal

Such as the title
I flashed the firmware in the first time when F4 Flight Control ported APM,At that time, the RX is still working normally on there.
But after the last upgrade, I can no longer connect to my receiver. Whether it is s.bus or ppm.
I saw that most of the forums are about the V3 version. But the difference between V2 and V3 is only a Jumper pad?
I am troubled. Hope for reply。

anybody? …

I’m not familiar with v2 explicitly but on my v3 I believe the jumper has to be in ppm mode to get sbus working on arduplane which was very counter intuitive.

Have you tried reflashing the version that worked?

thank you very much. I have not tried to roll back to a valid version. Because some bugs have been fixed in the new version. The current situation means that I can no longer use this version of the flight control?