Welcome and thanks for posting in the Community, @jc49.
There are times that the browser is full of frequently accessed page resources, causing some unusual responses. To isolate this, try logging into your QuickBooks Online (QBO) account using a private browser (incognito). Here's how:
Press Ctrl + Shift + N (Google Chrome).
Ctrl + Shift + P (Firefox or Internet Explorer).
Control + Option + P (Safari).
Once signed in, go back to the Apps menu at the left pane to double-check.
If everything looks good, return to your default browser and perform a clear cache. Every so often the cache becomes overwhelmed with older data which can potentially cause viewing and performance issues. Clearing it will refresh the system, and you'll be able to work with a clean slate. However, if the issue persists, try using other supported browsers or the external QuickBooks App Center.