InfluxDB batch insert only inserts the last line
I've tested it out and apparently you need the timestamps on the end of each line. Thus the file should look like: 

any,mytag=ab value=59 1555003566890381500
any,mytag=ab value=78 1555003566890381500
any,mytag=ab value=102 1555003566890381500


Now I wonder if you can insert them without the timestamp.