Crossover for new clearance

I had my fs poly in May snd was cleared in September. I posted before about how the sponsoring company told me they no longer had a position for me a week after the meet and greet. My clearance is in SC and I believe the CIA cleared me.

I recently signed an offer contingent on the crossover of clearance. I don't know which agency the new customer is. The new employer said it could take anywhere between 2-6 weeks.

Any reasons this could go wrong? At this point Im traumatized by the whole process. As mentioned above, everything is pretty fresh, CIA cleared. I do have foreign contacts including first degree relatives living abroad.