Splitter problem

Tv and internet went out yesterday.  Your advanced tch support grp determined that the problem was with my splitter.  In, out and tap type.  She had me remove splitter and go direct to modem, which worked.  Still no tv.

I have now reconnected the splitter with in from wall, out to modem and tap to tv box.  All working.  I am not sure how the splitter was wired before.  Does it make a difference with which outlet to use to modem?  This has been an intermittent problem which occurs and usually corrects itself overnight.