Macmail attachment forwarding issue

I have an issue with attachment in forwarded mails. If the mail is forwarded manually there is no problem with attachments. All the settings are correct (always include attachments etc.)

However If the mail is forwarded by a rule to another email addresses the attachment is not forwarded with the email.

I couldn’t figure out a solution and I also couldn’t find any info on that.

is there a way to solve that?

thanks for your support.