Audio Drop Out

I have two servers, each of which has audio (FLAC) which I stream. I have an active speaker linked by ethernet to both servers.
Until recently I have been able to stream music as one would expect. In the last week it has taken to dropping out for a few seconds and then starting again.
Both servers are dedicated machines doing nothing but streaming. I have noticed that there have been posts concerning drop outs and in some cases solutions offered, although this was linked to a problem with MKV’s.
Is there anything I could do?
I have optimised the files, but it does not make any difference.
Thanks for any guidance.