Missing Email Titles

I’m using EagleFiler to backup my Apple Mail accounts. A large number of my messages appear in the EagleFiler Library without their Title/Subject. I’m not trying to to do anything unusual… any suggestions?
EagleFiler 1.8.14
MacOS 10.14.6

Thank you!

That’s not a known issue. Could you export a few of the messages and send them to me so that I can investigate this?

Thanks for sending the test mailbox. EagleFiler shows 4 messages, 3 with subject “Re:” and 1 with an empty subject. This looks correct to me based on the data in the mailbox file.