Hello
I have the same issue as Werner Stangl.
Here are my csv file structures of original (left) and renewed (right) ones. There are no spaces or special characters in the field names.
I originally had strx and stry in my csv file. I deleted strx and stry since I do not use them and reimported the same csv in ArcGIS. For some reason, ArcGIS overwrites the variable names, strlon and strlat, with strx and stry (left one in the image below).
The correct names are imported only when I saved the csv file with a different name (right one in the image).
I could renew the name this time, but I do not want to do it every time I update my data in the future.
I have tried what is written in this thread such as:
1) Use TableToTable_conversion
2) Delete all the csv files from ArcGIS, save the project, create the csv file again, refresh the gdb, and import the csv again.
3) (I also tried) Reboot my computer to refresh everything
Unfortunately, none of them worked out since ArcGIS imports csv with a wrong field name in the first place. I suspect the same thing as Werner that this issue has to do with a cache for field names, but not sure.