When I was going through Triplebyte, I asked a lot of questions.

According to the recruiter I was working with, it could be 4-6 months between "refreshes".

I would say to keep trying to get in touch with them - everyone I interacted with on the Triplebyte team was nothing but helpful.

If you washed out of the process at the initial testing stage, make sure to let them know that you have been working on your skills and you are ready to re-take the test.