InControl2 SIM POOL - Initial Sim Pool Usage

Hello,
I am configuring sim pools for individual simcards, to monitor the data usage.
I am setting a 5GB initial pool size. Within a few minutes of starting the pool, the usage increases by 5GB. Within another few minutes, the pool size again increases by 5GB. The simcards are limited to 12GB, so I know this is not real data usage. Could this be a bug or am I configuring this incorrectly?

I should also note that I’ve deleted and re-created the Pools, so I am wondering if it is storing the sim IMSI in the background somewhere, and double/triple counting the sim pool?