Is there a > symbol at the top left where the refund monitor should be? If so, click that > symbol and the refund monitor should then appear.
Do you have "RaceMode" at the top where the refund monitor should be? Click the toggle next to RaceMode, or click Review on the right, to get rid of RaceMode and see the refund monitor.
There seems to be a bug that sometimes makes the refund monitor disappear in TurboTax Self-Employed. Clicking Review in the black navigation bar on the left should make the refund monitor appear. The problem has been reported.