I'm using Scribus version 1.5.5 on Ubuntu 18.10.
I created a table using the table tool. All of the cells in this column have center-aligned text, but in one cell (labeled "Steal"), the center line does not appear to be in the same place as the other cells in the column.

Weirdly, if I decrease the size of this text enough, it snaps back into place, as if the width of the field has increased.

If I take that same small text and right-align it, it snaps properly to the far right of the cell...

But, while right-aligned, I increase the size of the text back up again (to match the size of other cells in the column), it again snaps into misalignment, as if the text frame just shrank. In this screenshot, the "Steal" text is
still right-aligned:

As far as I can tell, this text is the exact same style as everything else in the column. It's not specially styled or aligned. For whatever reason, it's a text frame that acts as though it were the proper width at small font sizes, but much shorter in width at larger font sizes.
Can anyone kindly help me understand what's happening here and how to fix it?
Thank you.