The docutils.writers.manpage.Table class produces suboptimal table markup that causes display issues depending on terminal window size. This is because of the way the external table borders are specified.
Currently the class uses | and _ to generate lines for the external borders. The correct way to do it is to use the "box" option. If you do that, groff will take care of generating the external border itself and this one renders properly in terminals. I have monkeypatched the Table class in my project to do this, here is the code: https://github.com/kovidgoyal/kitty/blob/master/docs/conf.py#L550
The actual bug report in a downstream project: https://github.com/kovidgoyal/kitty/issues/5095
+1
Same issue
+1 from this groff developer
thanks for reporting