I guess You init the size and position of the main patcher before building the standalone, and then want to move it to last changed position in runtime. One could store the last position and try to loadbang it... Have a look into screensize object for monitor detection, and window messages to thispatcher, getsize, setsize etc

Thanks @Source Audio - yes, I realized just before bed last night, that I had set "Define Fixed Initial Window Location", and that perhaps I should rebuild the standalone without that behavior and see what happens. If no change, then those are good suggestions to look at, thank you!