Connections not flowing equally to pool with same pool member ip and different port

Can I suggest you provide more information about this - the software version, the configuration, the output of the commands, an iHealth link or suchlike.

I would be very suprised if this were a software bug, it is probably a configuration error - as you say, it could be that the pool is referenced by multiple virtual servers or suchlike.

Alternatively, raise a case with F5 Support and they will help you with troubleshooting etc