Thank you for the replies!
The odd thing is that on the site I am developing, the split occurred in an instance where there is only one word wrapped with an inline tag.
I got it to break in the odd way once or twice with this configuration in a pen, but it would not do it reliably. (sometimes break, then not).
So I did it with two words since it would always break.
I am going to see if I can replicate the exact issue in a pen.