My Vendor Balance Detail shows bill payments but does not deduct payment from running balance.
Welcome and thanks for dropping by the Community, @descanvelle.
I can help fix the issue you're getting in your Vendor Balance Detail report in QuickBooks Online (QBO).
I tried this on my end but wasn't getting the same result as what you're having. I also check if there's an ongoing issue about this, but there isn't currently one. In this case, let's perform some troubleshooting that can help isolate this issue.
To start off, log into your account using the incognito or private browsing mode. Your browser's settings or old cache might have caused this unexpected behavior while using QBO.
On your keyboard, press Ctrl + Shift + N (Google Chrome)
Ctrl + Shift + P (Firefox or Internet Explorer)
Control + Option + P(Safari)
Once logged in, pull up the report again and check if the balance is now deducted by the bill payments. If it works using the Incognito Window, go back to your main browser and perform clear cache to remove temporary internet files on your computer. You can refer to this article for more information: How do I clear my browser cache and temporary Internet files?
That's it! Please let me know how it goes after following those steps. I'm only a post away if I can be of additional assistance. Have a good one.