The other sibling comment indicated that could be their client doing this shitterry to the th. Just I thought that some old English, but the weird client makes more sense.

Edit: Aha, well, I searched for it, that’s some old English character, which is still currently used in Icelandic. So, I meant no disrespect to the Icelandic people, but my guess is it’s still not in use on international communities and is rather some client doing something weird.