You can use Tenants in ACI to achieve a functionality similar to VDC

Is it possible for you to upgrade to 3.3 and verify if this bug is an issue or your configuration.Also you can try pasting your netflow configuration here

Are you configuring the Tengig1/1/1 port instead of the Gig1/1/1 port.I think in the Catalyst 9200, if you use the Tengig1/1/1 port with 1G SFP you have enable and add the configs under Gig 1/1/1 interface.Let me know how it goes

You have remove the configuration for Nexus 2348TQ and downgrade as the Nexus 2348TQ was first supported in NX-OS 7.1(0)N1(1a), so it won't be possible to use it with 5.2(1)N1(6)