SL Voice starts cutting out with groups - help!

[Viggy Ruhig]

Hello, I use SL Voice a lot but when I get in groups of 4 or more, sometimes not right away, but soon enough my voice just doesn't transmit properly anymore...  It either doesn't activate (or doesn't catch my voice maybe) when I use push to talk, or cuts off early.  It's as if, I suddenly have a very bad SL voice connection, and yet can hear everyone fine (they just can't hear me properly)...  Even though nothing has changed from 15min ago when there were less than 4 people, I start getting significant problems. 

I use push to talk.
I have fast cable internet, and have no problems doing anything else in SL (including hearing others properly).
I use Firestorm viewer, with cable connecting in the settings. (I'd like to continue using this if possible)
I talk with people from around the world, and they all come in clearly and consistently to me and with each other. (it's just me with transmitting issues)

Any ideas on how to fix this?

THANKS!

Edited August 25, 2019 by Viggy Ruhig