To illustrate, I will use Visual Editor to edit the following page:
using Chrome Version 77.0.3865.90 running on Windows 7.
- Select/highlight (by dragging the mouse while pressing the left mouse button) the lead paragraph, which contains two citation footnotes. Then hit Ctrl-X to delete the entire paragraph. Only the part of the text after the first footnote is deleted, and some other text is now highlighted. Undoing with Ctrl-Z does not work.
- Start over editing the page, now highlight the text in the first paragraph from "born" to "Swedish", which contains one footnote. Ctrl-X works as expected, except that afterwards some text is highlighted that shouldn't be. Ctrl-Z does not work.
- Start over editing the page. Highlight the last word "Sweden" in the first paragraph, including the following footnote. Trying to delete it with Ctrl-X has no effect. Now try to highlight some other word by double clicking on it: it doesn't work, "Sweden" is still highlighted.
- Start over and again highlight the last word "Sweden" in the first paragraph, including the following footnote. Hit Ctrl-C to copy it, and paste it somewhere else. This works as expected, but undoing with Ctrl-Z doesn't work.