Ancestry doesn't have fact notes so you need to add it as a source.
Section 1. Fill out nothing - so no Source
Section 2. Fill out Details, example: Birth note, and place the note in the "Other Information" area.
Section 3. Check the fact the note belongs to. In this example it would be the birth fact.
It will appear under "Other Sources" and connected to the fact on Ancestry. But, in TreeShare it will show as a fact note.
Sorry to be so long about getting back on your post.
I have tried your suggestion and it does work. However, I've found it is maybe more efficient to work from the Web Hints screen and use the "View in Ancestry" button to see the hint. I then use the "Print Preview" screen in Ancestry to copy the desired info to my clip board. I then use the "Edit RM" button in the Web Hints screen in RM to go to the desired fact, source, and paste the Abstract into the details tab on the source. That way I do not have to create an "Other Source" and bring it back to RM.
I guess this is like beating the drum, but my biggest issues with the new tools for working with RM and Ancestry are:
1) Lack of functionality in RM to copy a fact (including notes and sources) from one tree person to another, and
2) The fact that using Tree Share and/or Web Hints will not bring the transcription/abstract of source details from Ancestry to RM.
I suspected there could be a problem with disconnecting and then trying to reconnect. At the very least I figured all my previously worked hints would probably show back up. I am checking all things on my PC and internet connection that might be contributing, but I suspect this is all due to the Ancestry server, band width issues, etc. Most of the time my connection works just fine, then I will hit a period of time where an update to or from Ancestry will significantly slow down or freeze. This sounds like communication issues, not software.