Steps to reproduce:

Expected: As long as there is room for the text, it should be possible to resize it smaller from any side.
Might be related to https://github.com/ampproject/amp-wp/pull/3259 and maybe https://github.com/ampproject/amp-wp/issues/3291
Interesting that this only applies to rotated blocks and when resizing from the side 馃
Yep. Will debug this in more detail to see what's happening.
Instructions for testing:
(See the gif in issue description for seeing how it should not be)
Verified in QA
Before:

After:

Demo of working as expected: https://www.dropbox.com/s/fuw2b3x1vytnbkk/demo-resizing.mp4?dl=0
Most helpful comment
Yep. Will debug this in more detail to see what's happening.