I think it can be fixed by changing this line to something like:

Select * from all_sequences where SEQUENCE_OWNER LIKE '<schema specified for sequence>';

https://github.com/NathanQingyangXu/hibernate-orm/blob/master/hibernate-core/src/main/java/org/hibernate/dialect/Oracle8iDialect.java#L493

Of course that would require passing the schema name to this function.