HHH-13322 breaks Oracle metadata retrievement when sequence are not owned by the user/shema but used through synonym. This is caused by the introduced query change from all_sequences to user_sequences.
Schema validation does'nt find the sequence anymore and failed.

I suggest to set the folowing query to manage both usecase :

select * from all_sequences seq where seq.sequence_owner = user or sequence_name in (select synonym_name from user_synonyms)

Best regards