I’d also recommend contacting your bank and verify if there are any ongoing issues on their end. Thus, it could be the reason why you’re unable to see your credit card charges.
When everything is all in place, you might want to check out this link for future guidance. This can guide you in matching your bank balance and QuickBooks balance efficiently: Reconcile an account in QuickBooks Online.
Keep me posted if you need further assistance managing your transactions or reconciling your accounts. I’ll be around ready to help you anytime. Have a wonderful weekend!