9ms is a relatively long trip time.
There’s no issue using it for FOH, but you have to be very careful when using it for monitors. I think 4ms to 9ms is unacceptable for monitor mixes
Depending on your setup, it’s definitely possible to create a system with a round-trip-time of less than 9 ms; with 1 ms Dante network latency and 32 sample periods at 96 kHz, we would expect to see a 3 ms total insert latency (1 ms network each way plus 1 ms internal latency), plus whatever latency your console routing or AD/DA conversion is adding. If you’re seeing significantly higher latencies than that, are you running at a lower sample rate perhaps? Have you measured thee insert latency of just your interface?