Glad to have you join the QuickBooks Community. It's important you're able to complete your reconciliation with ease. Rest assured, I'll be happy to point you in the right direction.
To get started, I suspect you may be experiencing browser-related issues that cause certain functions to cease such as the experience you've described. Clearing cache and cookies helps with fixing most browser issues. You can do this by following the steps in this article: Clear Cache and Cookies. I encourage you to give this a try on your browser when you get a chance. Otherwise, I recommend you to check out these helpful resources with more info about reconciling in QuickBooks: