The display is corrupted when the file is reloaded.
When viewing in the PDF viewer, if you modify and reload the PDF, some of the displayed characters may be missing. This bug occurs in 22.05.0, but not in 22.03.0. (22.04.0 is unchecked.) The PDF viewers I checked are evince and zathura.
For the two attached files, first copy foo1.pdf to foo.pdf and view it in the PDF viewer. Then copy foo2.pdf to foo.pdf with this view. When the latter is reloaded, the numbers are missing.