Phantom "Someone else is editing this note"

[SLB12 0]

A shared note regularly warns that "Someone is currently editing this note. Please try again later." despite the other user not having the note open. Same user switching devices allows editing to continue, but not on the preferred device. Troubleshooting has included exiting and restarting Evernote on affected device. Note is accessed via apple devices using latest Evernote app update.