Hello,
Thank you for getting back to us. We are working with a backup and security plugin that we use to oversee 100+ websites. We've been having issues tracking available updates on only one of our websites. Upon investigation with the support staff, they identified a value in the wp_options table that was not in its expected Integer form but had been changed to a String. We were able to isolate the problem down to the 'atum-stock-manager-for-woocommerce' plugin modifying the value.
Perhaps it is one of its properties that has been changed, and not the entire value. I have reached out to the other support team to see if I can get even more precise information and will get back to you. If there's any support you or your Dev team can provide, it would be greatly appreciated.