I tested on Windows and I see that the csv files Kibana exports are UTF-8 encoding.
For test data, I loaded this one doc with some unicode characters;
After I loaded it I realized that the standard analyzer parsed that string on things it considered currency and maybe others into 3 separate terms. I'm not going to worry about that.
So here's what I have in my data table visualization;
When I export that I get this;
If I just click on the csv file and select "Open with Excel" (Excel 2016) I get garbage;
But if I open Excel and use
Data > Get External Data > From File and check that the
File origin is
65001: Unicode (UTF-8) (mine was already set that way).
Then I can see that the data is the same as I saw in Kibana (and the same as the document I loaded except for the analyzing);
So please try to load your csv into Excel by this
Get External Data method and see if that works better.