It is
And it does matter as it creates spaces where there shouldn’t be any.
Can’t show an example as we have our site under maintenance right now.
Launching a renewed website is a pain when this is happening.
As for knowing how to work with the editor. Believe me, me and my team know. Creating a page goes wonderfully. Then going back in, to change a link and the minute you open it for editing, there are all the spaces on places where we definitely didn’t put them.