Outlook for Mac 16.65 (22091101) and S/MIME

I'm having issues with Outlook for Mac 16.65 (22091101) that when sending emails with digitally signed the embedded pictures are not received by the destination user or any attachment is also not received

for the mails it arrives with a question mark in the middle ... 

btw i've contacted the support and the answer was this is a known issue will be solved in future versions ...

any hints ?