What is the devil? After moving the vertical text box multiple times, the text box text overflows

As @Robert at ID-Tasker , suggests the text in the frame is set to Align to Baseline Grid

I'd say the larger frame has a (fairly large) text wrap margin applied to it. Impossible to tell without the full (Normal/Layout) display turned on, along with hidden characters. ALWAYS make sure we can see everything when you make screen clips; images of a box in two different locations doesn't tell much.

Do you have objects with TextWrap - even on hidden layers? 

Or align to baseline grid? 

I'm on my phone so can't check your file.