Does not make proportional when enlarging/reducing with shift key.

was directed here by someone else in the community when i couldn't find this thread with the same issue, it's fixed for me when i roll back to first beta release for Adobe Illustrator for ARM systems, hope that helps. I myself am livid they allowed a Beta to release without this function as it's pretty core to a fast workflow 

In the unlikely case you're fine with using it, the "free transform" tool will still allow constrained proportions but it's horrible to use. I'm leaning on the previous Beta release until they fix this and hoping Microsoft doesn't cause an issue with the older version when they run their own updates as it seems adobe and microsoft are currently chasing eachother in circles with updates trying to keep Creative cloud remotely stable for ARM