Strange Signature behavior...

I’m using the email signature. I add my name as follows using the Calibri font, with no extra characters for line feeds:
Mark
I save the signature. When I go back in to “Modify” I see that the “Mark” is in Calibri, but there is always an extra “space” at the end in Times New Roman. When I send/reply the signature looks good, but when someone else replies to me I notice the signature is all in Times New Roman - not matching the rest of the email body I wrote in Calibri.

Any idea how to fix this?

Can you please send an email with signature directly to me? Thank you.
wilson@emclient.com