I know is the tap itself is in a closet on the side of the condo next to mine and the pre-wired RG59 coax runs directly from there to my house. The heavy cable (don't know what it's called) that feeds the tap is coming from underground (or maybe an amp first?) I think. There are no telephone poles in my neighborhood.
Last night they ran a temp RG6 line directly from the tap to my modem to see if there was any difference. There wasn't. So it must be an issue before the tap.