You’re really looking in the wrong place for authentication.. Their actors (in all the formats).. It’s their job to act and an accent is part of the act thereby all accents are clones (as if they all attended the same accent college).. The reason it probably irks you is the fact that the majority of accents are spoken in the English language. If you caught an actor speaking either Russian or Ukrainian then you would most likely accept the accent. I too have a (slight) problem when actors/ actresses or even regular people speak English with a French, Spanish, Russian or any other accent.. It’s very easy to recognize authentic accents of those who (try) to speak the English language because they screw up certain words or phrases that an English speaking people (not knowing other languages) would never make, so yes.. there is a distinctive difference and it can rub the wrong way. Nice catch.