Sorry for answering this old topic, but I have the same issue. I tried to change buffer size in server configuration (multi room settings), but saving seems to have no effects.
I have to say that actually I don’t have multiple devices in a multiroom setup, but I brought up this topic because I thought these settings might help me solve the problem I mentioned in this topic. I’m not sure if my thinking is correct (if the two things are related); in any case, I can’t do the suggested group ungroup test.
Update: I’m almost sure it’s just a graphical interface issue. If you change the settings and click “save,” looking at the logs, it seems that they are applied. It’s just the UI that doesn’t update.
And from the responsiveness of the player on play.volumio, I get the impression that the changes are indeed effective (I increased the buffer responsiveness and the stream buffer time and I notice it when I click play or pause, and now the playback also seems more stable: I’ve been listening for half an hour on a PC that I’m also working on, with no dropouts or buffering).