I found a setting which helps this combination of module, ( Fibaro Roller Shutter 2 - FGR-222 v2.5 ) and motor. Parameter 22 sets the time out of the motor which is necessary because otherwise the Z-Wave module keeps powering the motor, even after it has reached the end.
It doesn't matter because the motor has its own limit switch, but if you press the button on the wall, then you need to press it twice, (once to stop the Fibaro from still keeping the motor running, and then again to do what you want). By timing, (in my case the curtains fully opening, or closing takes ~12 seconds), I set the motor to run for a maximum of 15 seconds, as per the picture below.
Now it works with just one press, no matter if it was operated with Z-Wave via Alexa, PC, tablet, etc. or the physical switch.
The other way to avoid the problem would be to set scene activation on, (parameter 50 to 1) and monitor when you get a single keypress, and run a scene that opens, or closes.
For some reason I can't turn on scene activation on one of my Fibaro modules, even thoough it accepts the parameter. Weird: one does, one doesn't. You need to press the physical button and scene activation variables then show up.