Welsh names suffer from it. They don't usually sound very nice in an English accent, and some sound quite different.
Rhys and Dylan seem to be Rees and Dillun. If you are called those names, if you are outside Wales you will have to put up with it.
Bethan is an example. In welsh the last syllable is pronounced en, like the letter N, but anglicised it becomes un.
Rhian is another example. It isn't Ree-un or Ree-Anne.
Popular on here are Nia and Eira. Nia doesn't sound like Near, and Eira isn't Ay-ruh ot Ira.
Arianwen gets suggested in Baby Names quite often, and I'm pretty sure that if used, they won't say it properly, as I don't think a welsh speaker would choose it. It's Ar-YAN-wen, not Arry Anwen. It is 3 syllables not 4.
I think it happens to Irish names- Roisin, Siobhan and Una spring to mind. The one Una I know complains that she gets called Ewe-na, Roisin gets Rosh-een, and Siobhan is now mainstream. Apologies for the missing fadda. They sound so much nicer is an Irish accent.
Names that I would compare to Xavier would be Robert or Richard. Same spelling but pronounced differently in different countries, and neither are originally English.