iCloud bookmark sync issues (iOS 13.6 & iPadOS 13.6)

Hi can anyone help with advice on an iCloud bookmark sync issue?

As a family we are having difficulty with getting Bookmarks to sync across various devices. Whilst other content chosen to sync via iCloud functions as expected (see attached image) our browser bookmarks do not sync consistently across all devices. On the face it of it appears that iOS 13.6/iPadOS 13.6 are where the problem lies as it is only devices running these operating system that are causing problems.

In an attempt to resolve the problem we have followed the steps outlined in https://support.apple.com/en-gb/HT203519 without success. Additionally users have individually signed out of their Apple ID on the effected iOS devices before power cycling/rebooting the device and signing back in again unfortunately also without success.

As an issue that we have been struggling with since a device upgrade introduced us to iOS 13.4 and something that may well have been present before our discovery in May 2020 hopefully someone within the community having already encountered the problem has already found and can offer a solution.

Thanks in advance..............