I tried it to see if I could reproduce the issue. Is this similar to what you were seeing? Sorry I don’t have any advice on how to fix it, but I posted some details for anyone who might know how to fix it.
I got this on Firefox for Ubuntu for anyone else trying to sort it out. The toolbar still says it’s Roboto Condensed and the same font size. I couldn’t get the formatting to stick unless I highlighted and replaced the current line. Hitting Enter would give me that huge number-bullet.
I may have been too close to the other paragraph and extended the list (that’s why the numbers are so large).