when i try to scale my objects on blender, they scale weirdly. the reason may have been because i applied rotation & scale to it (shift+a), but i'm not sure. i've tried redoing whatever i did wrong (changing pivot point and origin), but nothing seemed to do the trick.
before, i was able to scale the object on the video below as if it was one object (didn't scale weirdly)
i hope i was able to express myself correctly. thank you!
video of what's happening: https://imgur.com/a/ASu06Gv