Have you tried dragging the toolbar back with the ↔ cursor?
Keeping the EmEditor toolbar locations at bay is tricky. My recommendation is to set your toolbar locations for the window size you usually work with (e.g. maximised on your main screen) and then lock their locations.
In case you frequently hide and unhide toolbars: Set the locations with all toolbars shown, lock, then hide again.
I did try to lock the Macro toolbar, and Hide, then show again.
It still collapsed at the right side, and can not use pop up menu to show the hidden buttons.
Only “Macro toolbar” has this problem, the other Toolbars are OK.
Therefore, after Hide & Show, I will always need to drag the “Macro toolbar” out from the right side.
You may ask why not lock the Macro toolbar at the middle position.
Because another problem is, if I have many Macros on Macro toolbar, it have no “>>” button on the right end.
So it will not be able to click “>>” and then use the rest macro buttons.