existing symclone session "waits" for a later session to catch up

Hi, we have noticed that when an activated clone copy is running , if we then create & activate another clone session, from the same source devices, the first session will essentially stop copying until the second copy reaches the same point

for example we set off the first session of 26 source devices to 26 target devices
after 40 minutes when running a query we can see that 20 of the pairs are 100% copied, the other 6 are copy in progress

when we create and activate another clone session from the same 26 source devices (to different target devices) the 6 'copy in progress' pairs do not progress until the second cloning session has 'caught up' and then both sessions finish at the same time

is there any way of preventing the first copy session from waiting for the second to catch up?