I can help you sort things out so you can add receipts to expenses in QuickBooks Online with ease.
Sometimes, the stored cache for a long period of time can cause unusual behavior in the browser. Let's perform some basic troubleshooting procedures to check if you're experiencing a browser-related issue.
Start by refreshing the page you're using and logging into your QBO account using an incognito window. You can open it using any of these shortcut keys:
Google Chrome: Ctrl + Shift + N
Mozilla Firefox: Ctrl + Shift + P
Safari: Command + Option + P
If you're able to see the receipt this time, then you'll have to clear your browser cache regularly. This will prevent trouble on your browser moving forward.