Hello @BrianLester ,
I have found that copy and Paste from any online document - Google docs, Word online - ends up bringing over spurious characters and extra span tags. My workaround is to paste text-only, if you are on a windows machine CTRL+SHIFT+V to get just the text without any of the formatting. I then go through and update the formatting myself with paragraphs, bold, italics, and lists as needed. It's still a pain, but I prefer that to pasting and then selecting all the newly pasted text and clearing the formatting from the RCE toolbar.
I've never seen it do numbered lists on a straight copy and paste, but then again, I try to stay away from straight copy-paste. It could be that your source document has the numbered lists formatting and was altered to not look like numbered list.
Hope the advice helps on pasting text-only,
Cheers - Shar ⭐