On the left side, you can allocate the Flex licenses you have purchased to the machine types you will be monitoring.
Use the red + and – buttons to increase or decrease the number of
licenses to allocate to each machine type.
On the right side, the green read-only boxed indicate the total count of each machine type that is currently configured in Configuration>Machines
You will need to at least match the left side Allocation count to the Machines Configured values in the green boxes for the actively monitored machines.
The green count boxes also help you identify where you may have over-allocated your Flex licenses (if the left side textbox is higher than the right side green total count)

If your new license allocation does not
seem to have taken effect, you should try restarting that service in Services
or if the software resides on the CNC, then try restarting the CNC.