upi limits should not be depending upon the type of bank account
i am going to guess that it was a temporary issue at npci end. i would try doing another above 10K transaction from icici on dad's account (if he allows lol) and report back.
I don't know about acc type being connected to limits. My brother has a chase account in US and he is a private client of chase. Generally if you send money via zelle thu chase, the transaction limit is 2k per day but for private client it is 5k per day. It might be a long shot connecting US Chase bank rules to Indian bank bt whatever.
UPI is a purely Indian thing. It has nothing to do with any international banking standard or technology. And there has been no indication until now that banks are treating different types of bank accounts differently when it comes to UPI. At max they might eventually charge separately for UPI transactions for different types of baking customers. But even that is not the case at the moment I believe. Anyhow... My dad does not really have a basic account with ICICI. I think he has a ICICI Wealth Management Banking account holder because of an associated trading account.