Instagram not working with 12 Pro

I just got the 12 Pro on the 23rd and ever since I started the phone my Instagram isn’t working on my business account. I have a personal and a business account and anytime I make a post or story it always posts to my personal when I’m logged into my business page. I have even logged completely out of my personal account and it still doesn’t work and does the same thing. When I’m on my business account only messages from my personal account shows. I need this fixed ASAP. The phone is fully updated. I have deleted the app and reinstalled three times. Can someone help?