The Optimum Stop feature of the OPT function block in Menta / Building Operation Function Block Editor does not auto-adjust, even when the auto-adjust parameter is enabled.
This behaviour is by design, although it is not made clear in the Menta documentation. The auto-adjust feature only works with Optimum Start, not Optimum Stop. The optimum stop time is calculated from a fixed Outside Air Temperature vs time curve. As some compensation, both end points of the curve are manually adjustable for both time and temperature. For the optimum start, only the time parameters of the curve end points are manually adjustable.
The optimum stop curve must be manually adjusted over succeeding days until an acceptable stop time is achieved.