FY21AP autopilot system saves FPV RC model plane from being lost

Before I could set up the FY21AP stability and "return to launch" (RTL) system on my FPV model, I had to replace a broken switch in my JR 9X (9303) radio. To do that, I had to remove the FrSky 2.4GHz module and that requires unscrewing the antenna on the module.
Once I had replaced the switch and re-assembled the radio, I refitted the module and grabbed (what I thought was) the antenna from my messy workbench.
Although this antenna screwed into place correctly, it was the wrong gender to mate correctly with the SMA connector in the 2.4GHz module so I had no actual electrical connection between antenna and module. As a result, the range was reduced to around 400 yards -- just enough to fly into trouble.
Fortunately I had set the failsafe on the FrSky gear to switch the FY21AP into "return to launch" mode so, when the plane flew out of range, it simply turned around and flew back to the launch point -- whereupon it also flew back into range, allowing me to land it safely.
When I did a power-down range-test, I had less than 10 paces of range.
Using the *correct* antenna restored normal range and I've since flow out to almost a mile with this model without any further range issues.
I'll be posting a full review of the FY21AP to my RCModelReviews.com website and RCModelReviews YouTube channel very shortly. This is one very handy device and this is the second time it's saved my bacon.