I have the same issue. The EESDR volume control was working but now it's not. I don't know what I changed, but I'd like to know.
how are you using the RX audio ( How is it connected)
through PC, connected to speakers on the PC?
through headphone jack- etc.
If using PC make sure that the headphone button is lite up green (SIDE NOTE: I often have to turn this back on) as it doesn't always stay on every time, I start the program it is noted on GitHub and in the DEV group, if this is happening with you, I also suggest you use the GitHub issue reporter and note it as well