On my xiaomi 9T pro (non root) it is impossible to add an file / attachment via the paperclip when opening an new email. Even when i open the filemanager and select a file first and then choose to share it via k9-mail te files won’t be added.
Fe: jpeg, docx or pdf
I only can add an image file via my gallery. Only then it will add the file in a mail.
Using k9 5.806 from the playstore.
I compared all settings etc with my other devices, settings are the same, even the permissions (Samsung s7+ and an oneplus6 have no issues what zo ever)