Hello Lelnd,
Thanks for reaching out. The OneNote copy-paste issue on Android is known issue. It started in recent updates; version 16.0.19127.20224 works, but newer ones don't. The problem occurs when pasting from OneNote to another app. It seems copied but doesn't paste. This is probably due to changed clipboard code. No fix is available yet. Use the older version as a temporary solution. Download it from Uptodown if needed. speed up a fix by reporting it within the OneNote app by going to Settings >Help > Feedback >Send Feedback or you can report it through the Microsoft Feedback Hub on Windows or via their support page.
Do you need a safe link for the old version or steps to stop updates?