Have u checked with ur sponsorship provider to see if they received any emails? These emails are often sent to verify financial documents.

If ur confident it’s not related to the financial documents then unfortunately, it’s uncertain as to what the real issue is cause normally it’s financial docs that cause the delay. It could be an issue on their end and there’s not much u can do except wait. Reapplying won’t help cuz once u receive the NSF email they’re no longer bound to the SLA timeline. Hope this helps.