Question: What kind of a name is that?

...and why doesn't it display correctly? I just see a square where the fourth letter should be."

Answer: Well, it's a Hebrew name, obviously. Or rather, a Jewish name.

Or, to be precise, it's the kind of name that a Jewish person has nowadays, since in the times of the Tanakh a person did not have a family name per se, but was identified according to his or her father, mother, or tribe. In my case, it would be Pinḥas ben Avraham Avinu. Had I lived in the times of the Tanakh and had converted, I suspect I would have been identified by the people that I'd come from.

Pinḥas is one of the heroes of the Torah. Known in English (mis)translations as Phineas, probably borrowing the name from Greek mythology, he was the grandson of Aharon the Kohen. The name Phineas is infamous now in Christianity as the name of a society of racist bigots who use "Biblical principles" to justify violent behavior (and after all, what's new?). So I will stick to the original form of the name, thank you.

The "Ivri" part is both an attempt to identify more fully with my adoptive father (it literally means Hebrew) and a choice of family name. Because you can be as idealistic as you want, and wish for people to call you by your true "sefer-Torah name", and you may even convince many to do so. But you've got to put something on the mailbox and on the electric bill. And in my case, I'd rather not flaunt my European family name, with all its connotations of non-Jewishness.

And why doesn't it display correctly on your computer, if it doesn't? Because you're not using Unicode. See here, the site of the Jewish Encyclopedia for more information. (Obligatory disclaimer: I am not recommending all of the content of the Jewish Encyclopedia.)