No More Testing Personas?

We're experiencing a significant issue with our voice agent, which we were supposed to release soon. Until yesterday, we were able to run tests in Voiceflow under pre-set personas (which was essential, as we needed to test user authentication with phone numbers.) Now, when we go to test, there's no way to select a testing persona, which means we can't test anything (including user authentication.) This appears to be an overnight change that is having significant repercussions as we prepare to go live. Can someone from VF chime in, please? How can we keep testing?