Thanks for bringing this to the Community space, @s_creek. Let's work together to fix this so you can search your customer's profiles by their phone number.
In QuickBooks online, you can search your customer using their address or phone number. Since you can't see the customer once you enter their number, I recommend entering the first 3-4 digits of their number in the search field and see if you can view the related customer profile on the list. You can refer to the image below for reference:
However, if you're still unable to see them on the list, you can perform some troubleshooting steps to see if the issue is within your browser. In most cases, cache-induced browsers can affect the product's performance and cause some latency issues in the program. You can start by opening your account in an incognito or private browser. For easier access, you can use the following shortcut keys below:
Google Chrome: Ctrl + Shift + N
Mozilla Firefox: Ctrl + Shift + P
Microsoft Edge: Ctrl + Shift + P
Safari: Command + Shift + N
Then, look for the customer by their phone number. If it works, you can clear your browser's cache to eliminate them and start with a clean.
In addition, you can generate a Customer Contact Listreport to have the overall list of your customer's information on one page.
Let me know if you have other concerns about managing your customers or have any questions about QuickBooks that need my attention. I'm always available and ready to lend you a hand. Have a wonderful day!