@bmac: I've started experiencing the same issue, and although it's not a show-stopper, it is annoying and, for my part, a but worrisome. Clearly something that was working is now broken or functionality has been "downgraded". For me, I've started noticing this over the past few weeks, perhaps in conjunction with the October round of O365 upgrades. I've only recently migrated to OneNote to manage my tasks, and I've been very impressed with how well it interacts with Outlook. Anything that potentially degrades that interaction would be a concern. Hope this gets resolved soon.

Thanks for your reply. I hope someone can pinpoint the reason for this as it is annoying. I have checked the default apps but OneNote (the full version) is the default, so it isn't that.

Hi ! I too have been digging into this and have not seen any evolution, and this despite several cycles of O365 monthly updates. I also noticed that in these past several update cycles, OneNote does not seem to be impacted, implying that OneNote is not getting updated very much. A pity given how useful it is and given some great opportunities for improvement (such as grouping arrows and boxes to screenshots and other notes so that as the text above grows, the arrows and shapes applied to objects below - such as to underscore something in the screenshot - track with the object they are assigned to). If MS is not prioritising bug fixes in OneNote, I guess we'd better not hold our breath waiting for feature improvements.