Uneven Load balancing Round Robin in F5

What is the VS and pool config (redact as needed,  generic name/ips)  config along with the show VS and pool stats?

Are you seeing a different balance of concurrent flows over time or are the total connections to the pool members diverging over time? 

As stated, RR is a static method that doesn't take into account any current condtions other then pool member health. 

If pool members have changed health status, clearing the stats and observing over a time period of 100% health will get better data on this.