Getting exception when I try to use the throttler class with CqlSessionBuilder

Hello,

I've tried to use the throttler in different contexts such as CqlSession, Spark and DSBulk. I've tried to run the test at AmazonKeyspacesFixedRateThrottlerTest.java too but I have always getting an exception saying that a sync method was called from an async context and it can cause a deadlock and finishes the execution. I tried to debug but I could found what's is going wrong. Do you know how may I solve it? I tried both connect to keyspaces directly and by a VPCE.

Thank you