Uplinks from S5212F-ON SmartFabric TOR link up protocol down when connecting to a new Cisco 9500 core switch.

We added a VxRail 6 node cluster 2 years ago with a pair S5212F-ON for the TOR. Finally got all the bugs worked out and now are in the process of replacing our aging Core network stacks.

Replacing Cisco 4500+ with New 9500 switches.

When I connect the new 25g DAC's between the S5212F-ON and the stacked 9500's they show as OK=NO, Link=Up, Protocol=Down. The DAC we are using are programmed for Dell OS10 on 1 sSFP28 and Cisco on the other.

Config for the 9500 was migrated over from the 4500 that have been working.

In troubleshooting I've loop tested the DAC on the 9500 as it's not production yet which was successful. Also replaced the DAC with Dell EMC 10g sfp+ and Cisco 10/25g sfp that are the same as the current production connection. Every time I try to make the cutover, I get the same results. 

Both switches are able to see the transceivers, serial numbers and mac addresses. 

EMC network support is trying to help but can't do much because TOR are S5212F-ON using SmartFabric controlled by OMNI. They have even gone so far as to tell me I would need to bring VmWare into the call. 

Does anyone have any ideas? I've turned off auto negotiation and set speeds manually, changed the MTU to match. I see nothing in the error logs on either switch. Logs show transceiver inserted and turned on, but interface status shows protocol down. 

I have a set of active DAC and another set of SFP from a different manufacturer coming tomorrow.