I can reproduce using pyright, starting with emacs -Q:
M-x eglot
(setq flymake-show-diagnostics-at-end-of-line t)

Using the following file:

```
def print_hello():
    print("hello")

unknown_function


def another_function():
    pass
```

You need to resize your window so that flymake diagnostics are displayed on
multiple lines:
[image: Screenshot 2024-10-18 at 18.23.28.png]

Place your cursor on the `unknown_function` line, and then press down. Your
cursor will endup at the end of the current line instead of the next line.

Please tell me if you need more detail.
Thank you.


On Fri, Oct 18, 2024 at 6:09 PM Eli Zaretskii <eliz@gnu.org> wrote:

> > From: Romain Ouabdelkader <romain.ouabdelkader@gmail.com>
> > Date: Fri, 18 Oct 2024 17:09:19 +0200
> >
> > I found some unexpected cursor movement near diagnostics with
> flymake-show-diagnostics-at-end-of-line
> > enabled.
> > When the cursor is on a line with a diagnostic, pressing down will move
> the cursor to the end of the current
> > line instead of the next line.
> >
> > For example, pressing down here:
> > Screenshot 2024-10-18 at 16.57.29.png
> > Will move the cursor at the end of the line:
> > Screenshot 2024-10-18 at 16.58.09.png
> >
> > Also, when editing the last line of a buffer, new text will appear after
> the diagnostic until no key is pressed for a
> > few seconds:
> > Screenshot 2024-10-18 at 17.04.57.png
> >
> > Reproduced with emacs -Q on emacs 30.0.91
>
> Please show a full recipe for reproducing this issue, starting from
> "emacs -Q", preferably without the need to install any packages not
> included in Emacs.
>
> Thanks.
>