I've had somewhat different digital problems than what the folks previously posted. I started with Xfinity cable service. The installer ran used the previously installed cable that ran 150 feet around the house to the modem. Circa 1970 cable, whatever that was. Computer stuff, emails, web browsing, etc. worked perfectly.
Once I started streaming audio, I started having problems. Lossy formats were okay at best, high res ROON was impossible. I ran a cat5e cable though the hallway and across the floor to see if that would help. Well, it sorta helped at best. I struggled with this for a couple years until T-Mobile came along with their network. It was Wi-Fi to the house, I put their modem near the stereo and connected it up with a short cat 5e cable. Bingo! Way better fidelity! I could stream hi-res with out a problem.
My son is a principal engineer for an ISP in CO. He fixed up my connection with galvanic isolation, isolated AC Mains with a medical grade isolation, and picked out a solid network switch, all rated for cat 6e cabling. Digital has never been better in the house.
The problem is T-Mobile upload speed is very slow. I can't run the security cameras on it, I have to use Xfinity for that. Computer is now Wi-Fi to T-Mobile, and now that's slow. So the computer is back on Xfinity. Keeping two networks online is expensive!
I think the solution is to wire the house with good cat 6e cable and skip Wi-Fi. I called the three home theater companies in the area. Two would do the wiring if I bought all the equipment from them. The third doesn't respond to emails or phone calls.
I'm thinking of dumping T-Mobile, stick with low res audio, and doing the wiring myself when we get ready to paint the insides. Trying to get T-Mobile to upgrade their upload speed hasn't gone anywhere, they really aren't interested in increasing their upload speed to match Xfinity.
So, needless to say, I haven't bothered to play with audiophile digital cables. I'll have to get the inbound data right before playing with spiffy cables.