First. Make sure that the splitters are MoCA compliant (5-1675Mhz).
A 0-2.4Ghz splitter is engineered more for satellite systems. It can cause other problems by allowing high frequency noise ingress. You don't want to go that high. This is a good MoCA splitter;
Bear in mind that the splitters may not be the root cause of the issue. Just sayin'. Good luck with it
Thanks. Beyond the frequency range of the splitters, would that be too much signal loss?
It's more about those splitters allowing / not filtering high frequency noise ingress that doesn't belong on the frequency spectrum in which cable systems operate.
I'm a little unclear on whether each additional splitter degrades signal along the split segments only, or to the entire system.
Any splitters that are daisy chained / in series adds cumulative loss to that particular path. The individual ones don't affect the entire system, just the segments that they split.
I'm not quite sure that I understand the questions. Can you please rephrase them ?
We can't know if any noise is present whether the source is internal or external without it being tested for. Perhaps it would be best to get a tech out to investigate. They have the tool to test for noise. Splitters aren't designed to block noise but they do so inherently above their upper roll-off frequency. BTW, if you are using MoCA on your home network, there should also be a MoCA (POE/ Point Of Entry) filter present in the main coax line before the first splitter.
You don't want to use 2 MoCA filters. Get a tech out. Good luck !