A code example: in User A

CREATE OR REPLACE TRIGGER A.TRG1
AFTER INSERT ON A.TABLE1
FOR EACH ROW
DECLARE
...
BEGIN

...

END ;
/

After import to user B, it should be:

CREATE OR REPLACE TRIGGER B.TRG1
AFTER INSERT ON B.TABLE1
FOR EACH ROW
DECLARE
...
BEGIN

...

END ;
/

The problem is , the code is below after import to B

CREATE OR REPLACE TRIGGER B.TRG1
AFTER INSERT ON A.TABLE1 --the owner is still B
FOR EACH ROW
DECLARE
...
BEGIN

...

END ;
/