Telemetry gets HUD data but not parameters

My x-rock telemetry transceivers make a good link and download the hud data right away, but that’s it.
They then open the parameter widow, and claim to be downloading the parameters, but then the window just sits there. Empty progress bar, no motion. Oddly, if I wait long enough – maybe 8 to 12 minutes- they will start downloading and do it fine-- normally.
I reloaded the sik software, copied to each, moved them further apart, swapped them, no luck.
What to try next?
The fact that they link and do get the HUD data down means they are working, I think