There is no problem with any of your modems, splitters, etc. As of a few weeks ago, Rogers internet service has just been wonky. Naturally, they will NEVER admit this to you. EVER. They will try and stall you and take you through the usual troubleshooting routines ('power cycle' the modem, get a new modem, etc etc). Anything to avoid the real issue:
Rogers internet just STINKS currently.