Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: NVIDIA GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 466.63
Broken: version: 2.93.0, branch: master, commit date: 2021-06-02 11:21, hash: rB84da05a8b806
Worked: No known working builds
Short description of error
Scale to Fit text boxes will unexpectedly overflow onto a second line when text font scale is less than 1 (Font > Transform > Size = 0.5)
This error is easily reproduced when following the same steps, however it is difficult to find the steps that lead to a new instance of this bug.
Exact steps for others to reproduce the error
The linked .blend file should open displaying this bug, however if this is not the case you can reproduce by choosing a confirmed font:
and many others
Type in a text within the bounds of the text box and then simply add one character at a time until you encounter the error
For my testing I was using "SOME TEXT HERE" and adding "a" until I got a line overflow.
In my example, one character more or less and it acts as expected.
Sadly this bug appears to depend on font, starting text, number of characters added, font size, and text box size. With so many variables, I have had a difficult time pinning down the root issue.