I don't think you ever mentioned having so much extra cord before or I would have suggested a shorter one. But probably the damaged one was the biggest problem.

Generally for anything - TV antenna, phone, modem and cords connecting any of those types of things - the shortest length is the best way to go.

All the extra length can degrade the signal of whatever is traveling thru it.

I recall reading about antenna cables and if they are coiled the current can jump and degrade that way- so maybe for phone/dsl it can do the same.??