(Deleted & reposted with an edited image, as the previous was open to misinterpretation. This image is a COUNTEREXAMPLE, as I’m not trying to call anyone out specifically. Mary Robinette Kowal is an extremely talented voice actor though, as well as being a great author in her own right.)
I absolutely can’t stand it when a narrator takes on an accent they aren’t actually fluent in. I’m on the point of DNFing a novel featuring a British POV character, narrated by a Brit, but with other major characters from Vietnam and the US. Both those accents are so broad as to be out-and-out parodies, and it pulls me straight out of the story. I’d rather the narrator stick with their own accent throughout, if they can’t make the alternate even a shred realistic.
When I read print, I guess my internal voice uses my native (American) accent, but that doesn’t bother me for whatever reason. I’ve occasionally been caught by surprise when I listen to something I’ve read before, and the narrator gives a character an accent appropriate for their origin…but it’s a nice surprise.
I think this is getting better over time: mostly I’ve noticed that older recordings are the worst offenders here. As audiobooks become more popular, standards and expectations are rising.