I had a recent request from a product owner to style the subject line... I said we can't do that and that I don't want to live in a world where senders can change the font or size of the subject in an email.... Can you imagine the crap we would have from spam in that case?!
Ah, I referred to the third line, "𝔻𝕠𝕖𝕤 𝕥𝕙𝕚𝕤 𝕨𝕠𝕣𝕜? ", as the "second one" in my message, without mention for line 2, which renders correctly, fortunately. But thanks for the heads up.
Firefox Mobile renders it well for me, are you sure that the comment is not rendered as it should be (with garbage from line 1 overflowing over line 2)?