I got the "we are unable to replicate this" line from Support. I sent them an example, but no joy on that. I gave up, not having the time to waste in trying to get somewhere down that road.
My work-around:
1) Never delete the copied bullets from a note until you're sure they've been successfully pasted into another.
2) When you can't copy from outside of EN (eg gmail or a web page), try copying everything up to the last punctuation mark, as in. Copy all of the sentence until you get to the period, question mark or exclamation point -- don't include that final mark character in the highlighted text. That's worked for me some of the time.
3) When you're copying from EN to a web article you're writing, I've found that the "don't include the final character" trick -sometimes- helps. Not always.
3) always try to paste copied content at the end of a bulleted list.