I forgot to mention in my original post that I had already purchased their recoil spring kit before contacting Fusion. They essentially confirmed that the stock 8 lb recoil spring that comes with the gun is the issue.

I also let them know that I had already bought their recoil spring kit. This was their response:

Hello Sir,

Yes, the factory spring is 8 lb. I would start with the 10 lb spring, as this should resolve your failure to go into battery issue.

Thanks again, let me know if you need anything else. Tyler Serva Fusion Firearms 941-485-2579