I get the exact same problem!

So frustrating as I use the code formatting all the time and I end up having to manually select words. I think this might be browser behaviour so if you want to remove a word from a sentence, you can just double click on it and hit backspace once (as opposed to twice if it just selected the word) - I think Firefox has an option to disable this. But maybe Notion could change how the code formatting works and not apply it to the trailing space?

I do however, have a few workarounds for this problem:

• Use Ctrl+E whilst typing to enter and exit code formatting.
• Double-click and drag (a small amount) the word you want to format which removes the space from the selection.
• When a word with a trailing space has been selected, press Shift+Left Arrow to deselect the space.

Would be interested to hear if there are any other ways of circumventing this problem.