Okay Nate, I think I know what's happening, I just don't know why it's happening.

When you click on Reply to Message, you get the new screen with the cursor flashing within the new message body.

When you click on your Canned Replies, the cursor goes away from within the body of the message. If I'm not mistaken, when you do this with the old software, the cursor would always continue to blink within the body of the message. So, for some reason, it's losing it's place within the body of the message when you click onto your canned replies.

My guess is that when you lose the blinking cursor the canned reply can't copy your repliy to the body of the message. Seems like it gets lost.

Maybe this will help.
Jim Smith