I think that the 'it was all so alien to her' explanation for Meghan's discomfort and Megxit is often overcooked.
Meghan is a self-declared intellectual and autodidact. I'm sure she's had ample opportunity to read loads of books about the British RF - for me I'm constantly eating up Alison Weir, Dan Jones, any popular history book on the Mediaeval RF I can get really. It FASCINATES me. There are plenty of such books on the 20th century RF - Andrew Marr and D Starkey both have books that are impeccably well researched yet easy and engaging to read. Perfect for someone with a busy schedule, like Meghan.
Also, Meghan is a self-declared empath and woman of the world. Also had what she has described as a significant humanitarian role with the UN. As such, she would have been well aware that different cultures can often seem alien and strange, but with observation, hard work and humility in asking for help, one can come to understand them far better.
So in conclusion I find it hard to believe that an empath, intellectual and humanitarian such as Meghan found the idea of different cultural practices so difficult to accept.
Perhaps the real problem was that she was not treated with the deference and admiration she felt she deserved. Probably not the best PR to admit that publicly, though. Far better to pretend that people who curtsy, or people who don't like hugs, or people who are not glued to email 24/7, are an alien species which it would be impossible for anyone ever to understand.