Have you paused it at all? Even by accident? Done any time changes? This can affect the time for the matchmaker to come but she will typically at 10:30AM, 3:00PM, and 6:00PM.
If you think your tama is ready and has been an adut long enough, you can set your tama to 10:29/2:59/5:59 respectively to force the matchmaker to come.
Do note that SOME V4s are prone to have issues with the matchmaker coming on the screen but leaving REALLY fast so keep your fingers on the buttons.