Do the following:
generate a simple online text in libreoffice24.8.2.1-1.2,
export it as pdf (or print it with cups-pdf-printer)

from poppler tools use "pdftotext"
it will now have the char hex 0c at the end.
(behavior is same if its somewhere in middle of text)

do now:
in X-session:
textwith-0c -> xclip -> x-clipboard (ok, the text is shown in clipboard and
could be pasted (mouse/middlebutton/strg+v))

in wayland-session
textwith-0c -> wl-copy -> wayland-clipboard (did not show contens when 0c is
used, not possible to paste (mouse/middlebutton/strg+v))

i am not sure if this is a problem of wl-copy or the wayland clipboard itself.
when using wl-paste the contens will be outputted.
but its not show (maybe never arriving) in clipboard of the desktop
the enviorement: (plasma6.2.0-1.1 kdewayland6.2.0-1.1 all on opensuse
tumbleweed 20241011)

workaround is to filter out the 0c of the textfile.

commands used:
x-session:
pdftotext -layout libreoffice-pdf.pdf - | xclip
pdftotext -layout libreoffice-pdf.pdf - | xclip -selection clipboard

wayland-session:
pdftotext -layout libreoffice-pdf.pdf - | wl-copy
pdftotext -layout libreoffice-pdf.pdf - | wl-copy -p

and here one possible the work around:
pdftotext -layout "$1" - | sed -e 's/\x0c//g' | wl-copy
pdftotext -layout "$1" - | sed -e 's/\x0c//g' | wl-copy -p

filed also a bug for wl-clipboard:
https://github.com/bugaevc/wl-clipboard/issues/237