When text containing footnotes is cut from a document, the footnotes are removed from the document (this is the correct behavior). However, the footnotes are not preserved. When the text is pasted, leaflet correctly identifies the footnote references as such and renumbers the footnotes appropriately. However, the footnote originally attached to the text has been destroyed and is not recreated, even in an empty state.
The end result is that the document will contain footnote references without any corresponding footnote, and if there were footnotes following the location where the text was pasted they will now either be referencing the wrong footnotes or nothing at all, as the pasted text has effectively "stolen" their footnotes.
This behavior has been observed on both firefox for android and firefox desktop. I do not use chrome so I don't know if the behavior exists there as well.
I have a similar issue when copying markdown text with footnotes into leaflet. Leaflet seems to understand that there are footnotes in the text but does not connect them to the contents of the footnote. The published text then shows "empty footnotes" at the end of the text, keeps my markdown footnotes as part of the normal text at the end (just before the "empty-footnote block").
When I try to fix the first footnote, via editing the leaflet text,
But at the end of the text all before erased footnotes re-appear
but also at the very very end the leaflet notes are empty
Observed on firefox and safari (desktop).