Outlook moves footer picture to attachement

I have created an email footer in Outlook. It consists of: a logo in the form of an image and text data. If I send an email without signing or encrypting by PGP everything is fine. But when I send an email signed or encrypted by PGP, the image from my footer is transferred to the attachment. Why is this happening? Can I prevent my logo from being transferred to an attachment after encryption?

Which version of Gpg4win are you using?

Did you enable the option “Send OpenPGP mails without attachments as PGP/Inline” in the settings of GpgOL?

Are you using Exchange or IMAP/SMTP?

I’m using Kleopatra (Gpg4win -4.1.0).

Yes, I already have “Send OpenPGP emails without attachments as PGP/Inline” option turned on - it didn’t help

I am using the Microsoft Exchange account type

This is sadly a known issue. https://dev.gnupg.org/T5709 But as the alternative that allowed this was causing “real” attachments to be hidden accidentally the current implementation is rather not pretty / user friendly but won’t result in apparent data loss.
And PGP/Inline won’t help because the image will always count as an attachment.