Gives "Invalid transaction id value" when I try to refund a transaction in sandbox

[tnvr000]

If I try to refund a transaction(done in production) in staging(testing/sandbox), it gives error(Error Code: 10011) "Invalid transaction id value".

What confusing is that if I refund a transaction(done in sandbox) in sandbox, OR transaction(done in production) in production, it is successfully refunded.

It used to work perfectly fine, until recently.