Formatting errors in replies/forwarding

The line spacing in replies and forwarded messages is too big.
The original formatting should be kept!

This was OK in previous version 8.x.
Problem occurs since update to the version 9.0.1708.

Looking at this I think the line spacing in the original is actually too small. The lines shouldn’t be so close together.

But whatever the case, I can have a look at this for you to see what is specified in each. I will need a copy of both the original and the reply. To do that right-click in the body of each and choose Save As. Send me the eml files this creates for each one.

Thank you, Gary, for your answer.

I investigated the problem more closely, now it’s clearer what the issue is. The display is correct in both the sent and the received email. The line spacing IN THE EDITOR is too large (see attachments). After sending and receiving the mail the sizes are OK.
This behavior in the new version is still very annoying.

Is this quoted text, so from the original message you are replying to, or new text you are typing?

The content was copied from a previous mail.

I can reproduce the same issue if I use a signature (e.g. Arial 8). The signature appears different in the editor of a new mail and in the editor of a new reply message.