Didn't have this problem until a patch or two ago. Of course, before the patch I would always be thrown into area chat, which was annoying, but at least I could just leave it.
NOW what happens - my VC NEVER works upon starting ESO for the first time. I have to completely load into the game, exit, and restart it for the in-game voice chat to work in a group.
Then, randomly, the game will hit a lag spike and kick me out of voice. Happens without fail every time after about 20-30 minutes give or take.
I've deleted my settings via my PS, clearing cache, even rebuilding the PS database. The only thing I haven't tried is reinstalling the game since it will take about 13 days to download and reinstall it again since the "copy" process for ESO patches takes forever.