When a member sends a message to the owner it shows up in the Activity section with a link to see the message. I usually use that to reply to those messages, hitting the reply button at the bottom of the message there. I noticed over a week ago that when I hit reply to the message, the subject line is blank, not showing the subject that the member sent the message with. It used to show the subject line with a "Re:". So, I've been copy and pasting the subject line in.
Related, when a non-member sends a message to the owner, that message is not clickable. I must reply to it from my email. There must be a technical reason why that is so, that I am not thinking of.
Further related, as I've mentioned a while ago, it would be nice if when someone sends a message to the owner address, the system would reject the message without a subject line, just like it does when a member sends a message to the group, which is one of the best little things about groups.io! Another one I love is rejecting messages people send with attachments (when attachments are not allowed), which eliminates the necessity to reject the message for "missing" something.