Hi,
Unfortunately you can't "convert" or "breakout" the 40GE interfaces to get four 10 Gigabit Ethernet interfaces from each port. As per the Cisco Nexus 9300 Platform Switches Data Sheet:
"The 40 Gigabit ports on the uplink module do not support the break-out mode of four 10 Gigabit Ethernet ports, but they can be converted to a single 10 Gigabit Ethernet port with the QSFP-to-SFP adapter (QSA)."
The only option is to use the Cisco QSFP to SFP/SFP+ Adapter (QSA) module (part ID CVR-QSFP-SFP10G=) which gives you one 10GE interface from each 40GE interface.
As far as I understand it, this is a hardware limitation of the Cisco ALE (Application Leaf Engine) ASIC used on the expansion modules.
Regards
