I'm not sure what the exact problem without looking at the project, because it could be a number of things.
I usually have this problem when I have something on a layer with a parallax other than the 0,0 or the 100,100.
My suggestion is to click on the textbox, find out what layer it is on in the properties, and set Parallax in editor to yes. This will show you where the textbox will start in relation to the parallax set.
Also, does the textbox have any behaviors like anchor? Anchor will reposition the textbox automatically.
Usually with glitches, I find deleting the item(if not too hard to redo) and making the item again is helpful.
I hope this helps!