Hi EricOpitz
For your reference, there is an errata that discusses potential HPS performance considerations related to the L3 cache, which you can review here:
https://docs.altera.com/r/docs/825514/current/agilextm-5-es-device-errata-and-user-guidelines/degraded-hps-emif-performance-with-2mb-l3-cache
To better understand whether this may be applicable in your case, could you please confirm if your device part number is included in the list described?
If possible, kindly share the exact device part number so we can help review it more accurately.