I've a converted solution but the described issue does not appear...
I also do NOT have this problem with scripts in convert files (at least not yet).
This reminds me of some reports of old scripts and value lists which were missing key pieces but were not editable after the file was converted from much earlier versions of FM and then couldn't be edited or fixed in FMP/A11.
Are you able to edit the scripts which you cannot move?
If not, there may be a file problem.
If yes, then try editing it, save it, and then try moving it.
Let us know what you find.
Try recovering the file...