The issue is caused by the theme used, not by sddm itself. If the theme is part of debian you should reopen the issue against that package. If it's installed by the user, contact the developer directly.
Best.
--
Salvo Tomaselli
"Io non mi sento obbligato a credere che lo stesso Dio che ci ha dotato di
senso, ragione ed intelletto intendesse che noi ne facessimo a meno."
-- Galileo Galilei
https://ltworf.codeberg.page/
