1. What is the status of datafile '+DATA01/DEMO1/DATAFILE/undotbs7.3682.1003925829' in teste master database ?
2. Check that both compatible.ASM and compatible.RDBMS are 188.8.131.52 or newer.
sqlplus / as sysasm
SQL> select name, value from v$asm_attribute where name in ('compatible.asm','compatible.rdbms');
3. If access control is not already enabled on the disk group that contains the test master's data files, then enable access control on the disk group.
SQL> select name, value from v$asm_attribute
where upper(name) in ('ACCESS_CONTROL.ENABLED')
and group_number in (select group_number from v$asm_diskgroup where name='DATA1');
4. Did you put test master in read only mode before running `dbms_dnfs.clonedb_renamefile` ?