I have observed degraded streaming from time to time. I have a well isolated setup with 2 of the Jcat M12 switches cascaded into an Uptone Ether Regen w sfp to my server.
While I do not see the daily fluctuations I do notice a degradation over time and found that a hard reboot of my router gets the sound back to where it should be.
The scripted "Perform a hard reset" is what they always say to do when we call for internet problems, even though it usually has nothing to do with service being out.
From what the internet people say, the reset will reset the connection on their end as well and there is a whole host of things that they are doing in the background that can effect the network connection. We were being throttled frequently and once we were told that there was more than 1 person on out IP address.
Who knows what is really going on on the provider side however for me I will reset the connection at least once a week.