You had a receiver failsafe. You can’t always trust RSSI reading in the headset, for example my R9m equipped quad never reads correctly in the HUD no matter what I do yet it stays solid in the telemetry screen on the radio.
You need to look at what firmware you are running across the board, both in the TX and your receivers. Any mismatch in FRsky firmware is always bad. If both are running the same firmware then look at antennae and how they are placed. I have had FRsky receivers that were consistently appalling whatever I did, the RXSR I had being one, in the end I just smashed it with my favourite hammer and tossed it in the bin.
These are all illustrations of why many people are ditching FRsky equipment, their whole range is a mess right now, the firmware situation is too complicated and unreliable and they keep making crap receivers that don’t work whatever you do!
If you want all these problems to end then the majority view seems to be to buy Crossfire. The Crossfire Lite is affordable and works very well. This is the route I am taking after my wallet recovers from Xmas. I just feel like FRsky is no longer reliable and none of my gear is Access compatible so rather than spend more money with a company that doesn’t care about reliability I am going to accept the failings of TBS instead. At least the prime parts of their system work and they don’t actively try to stop customers using older gear.