It's great to see you back in the Community. It's my priority that you're able to get this resolved as soon as possible.
After researching this issue further, I've discovered that there's an on-going investigation about vendor credits. This means that other users are having the same problem. With that being said, I recommend contacting our Customer Support Team. They'll be able to add you to a list of affected users that will send you updates via email. Here's how:
Go to the Help icon in the top right-hand corner.
Click the Contact Us button.
Type in the investigation number as the description (INV-55709) and hit Let's Talk.
Scroll down and choose to Get a callback.
For future reference, check out our tutorials page to review other features that are available to you in your QuickBooks Online (QBO) account.
Let me know how the call goes. Should you need any more assistance, feel free to ask. I'm always here to lend a helping hand. Have a wonderful day!