Beforeigners
I happened across this this short Scandi-series (with subtitles) on HBO and I have really enjoyed the first couple of episodes. It's a normal day in the modern world when, around the globe, people suddenly appear in water with a flash of blue light. They have no idea how they got there. This phenomenon continues for several years and looks like it will continue.
The "beforeigners" are from the correct geographical location but they come from three time periods - Stone Age, the 1300's and the 1800's. Some integrate with the modern world, or try to, but a great many prefer to keep the way of life they are used to, modern laws permitting... but there is good and bad in us all.
https://www.youtube.com/watch?v=XCm1SMSHdhA