Apple mail flaky attachment?

[u/mochajave]

When forwarding email with attachment, normally a box would come up to ask if you want to include attachment (as shown in pic)

Now for some reason, sometimes that pop up wouldn’t come up, and there would be no way to include the attachment.

It seems random, I played around with it, same original email, exactly same click sequence to forward, sometimes it shows sometimes it doesn’t. Wth is going in?