Had similar problems with Fios TV One at house we moved to four months ago. There is one main DVR With coax connecting from the new Fios router in basement (with a MoCA 2.0 splitter running coax Cable to router and to Fios One dvr; one client set-top box with coax on main floor (and a fios wifi extender on second floor). From the get go, we noticed cable tv programs freeze up, or Netflix through Fios not connect or freeze, or On Demand menu not loading, on demand movies freezing. Picture quality was unaffected. At first I thought it was only the client box. Rebooting / trying to reconnect worked for a few minutes. ONT is outdoors on side of house. I noticed that two coax cables run from the ONT, a pre-existing black coax cable from an earlier installation, and the new coax cable from the Fios service upgrade when we moved in.
I called VZ and went through troubleshooting, swapping dvr and client on the two floors, to no avail. They suggested replacing the coax cables, but I wasn’t ready for that step. As it happened I had an extra MoCA 2.0 splitter from our previous-house Fios setup. There was an old splitter rated for ?5-1000MHz outside of the house. I replaced it with the VZ MoCA 2.0 splitter (rated to > 5000Mhz), and voila, problem seems solved. Cable programs and on demand stuff has been working smoothly for a few days now.It all came down to a splitter mismatch (the old one was not up to spec), so if you have more than one splitter in your house, I would suggest trying that.