Hi,
Please read the instructions of features on the main page to understand everything better.
For convenience, once you assign a profile it cannot be removed from that account for the rest of the trading day, once the new trading day has started whatever is assigned into the "Tommorow's Profile" field would be the new profile.
The "Reset" and "Reset All" buttons are meant for resetting tommorow's profile only.
so to summarize, a profile assigned to an account cannot be changed for the same trading day.
also check out the new rollover feature in the settings menu, it lets you decide when the next daily reset occurs.
Best,
Aviram.