iPadOS 16.7 insisting I purchase cloud+ storage

Recently my iPad insisting it can’t be backed up without upgrading to cloud+. I have used about 4.3 of 5gb standard cloud storage, and backup say my next backup only increases this by 28mb. The bar chart in settings->iCloud shows more than enough free space for this backup. However main screen of settings always shows “your iPad can’t be backed up” and prompts me to purchase iCloud+. If I go into iCloud backup I. Can actually backup the iPad successfully but yet settings repeatedly tells me that I can’t. Seems like faulty software.