Playback often halts for a fraction of a second

[febs]

It happens on average every half-an-hour.
Playback interrupts for a fraction of a second and then automatically continues.
I believed it could be something done by snapcast to ensure sync on all nodes. I couldn't find anything but these in the logs of one of the snapclient units:

May 07 07:30:34 bebelini snapclient[1206]: pMiniBuffer->full() && (abs(pMiniBuffer->mean()) > 50): -264294
May 07 07:31:15 bebelini snapclient[1206]: pMiniBuffer->full() && (abs(pMiniBuffer->mean()) > 50): -296292
May 07 07:32:21 bebelini snapclient[1206]: pMiniBuffer->full() && (abs(pMiniBuffer->mean()) > 50): -158328
May 07 07:32:26 bebelini snapclient[1206]: pMiniBuffer->full() && (abs(pMiniBuffer->mean()) > 50): -151621
May 07 07:32:41 bebelini snapclient[1206]: pMiniBuffer->full() && (abs(pMiniBuffer->mean()) > 50): -158751
May 07 07:32:46 bebelini snapclient[1206]: pMiniBuffer->full() && (abs(pMiniBuffer->mean()) > 50): -280537
May 07 07:33:51 bebelini snapclient[1206]: pMiniBuffer->full() && (abs(pMiniBuffer->mean()) > 50): -324429

Is that related?
If not, what can I do to mitigate or solve the issue? Could it be a matter of router used?
Thanks.