EIGRP Traffic-share Balanced command

Hello all, looking for clarification with some unusual results I am having on a basic network.

I have a small router network with 2 equal cost routes between R1 and R2. The Max paths is set to 4,

when setting traffic-shared balanced and starting several session flows across the network, all of the traffic utilises one link only.

I thought the traffic-share balance mode would distribute the individual sessions across both of the routes, Am I wrong?

When configuring for traffic-share min across-int, the traffic is distributed between both equal cost links as expected.

Any suggestions are greatly appreciated.