Hi @JacobVanVleet,
This is likely something that will need to go to Canvas support (if available to you) to investigate. There have been a couple times in the 10+ years we've had Canvas that I have ran into something like this, but never anything consistently reproducible. Canvas will only process one SIS import at a time, and any additional import attempts will basically get queued. If one import gets stuck, none of the subsequent ones will process. Hopefully support will be able to unstick the import or cancel it so the others can all process. If they are all failing, support should be able to identify the cause for you as well.
I wish you good luck in getting the issue identified and resolved!
-Chris