How to deal with possessed arrow attachments
Arrows like to do squirrelly things when you things under or near them. Stretch a layout box and arrows can become possessed. Similar things can happen in plans, sections, elevations...
A sneaky way to tame them: Select the arrows, Ctrl-X to delete them and store them on your windows clipboard. Make your edits, then Ctrl-alt-V will put the right back where they belong, pointing right where they always dis.
If your edits will require the use of the window clipboard, park them in a new blank plan file (again with Ctrl-Alt-V or Paste/hold) for safe keeping. When you're ready to bring them back, copy (Ctol-C) or cut (Ctrl-X) and paste/hold (Ctrl-Alt-V) works like a charm.