the problem is not that you used the old form of GLOB_SCALE in the paramscript, but that you used it at all. It’s still there, causing the “rubber band” to fall off in any other scale but 1:100 (that is the dummy default of this global in paramscript: it’s not containing an up-to-date value any more in AC20).
If I’m correct, you use the GLOB_SCALE to keep your object in paper size. You can do that without this global, see my post a bit further up (about editable hotspots for paper size). Sorry if I did not get your intention, but hopefully that will solve your problems with the object.