Just tested - no issues like mentioned. Fresh transformation file with same default settings:
*OPTIONS
FORMAT = DELIMITED
HEADER = YES
DELIMITER = ,
AMOUNTDECIMALPOINT = .
SKIP = 0
SKIPIF =
VALIDATERECORDS=YES
CREDITPOSITIVE=YES
MAXREJECTCOUNT=
ROUNDAMOUNT=
*MAPPING
*CONVERSION
Sample string from text file with exported data:
BE1000,DIRECT,2020202010101,2011.JAN,ACTUAL,1200,-0.2300000
My BPC version is BPC10 SP14, BW 730 SP12
Vadim