I have a 2017 iPad Pro on iPadOS 13.1.2; iPhone 11 Pro Max on 13.1.2; and 2019 MBP on Mojave 10.14.6. All devices logged into my iCloud account. iCloud syncing of Safari bookmarks and open tabs works fine across all three devices. Browsing history, however, only seems to work between the iPhone and the MBP. The iPad doesn't sync its history at all -- pages viewed on the iPad do not show up in the history on the iPhone or MBP; likewise the iPad doesn't get any of the history from iPhone or MBP.
I did try turning off Safari syncing in iCloud settings on the iPad, and chose not to "keep" any of that data when doing so. I confirmed that the history/bookmarks/tabs were wiped, and then turned syncing back on on the iPad. I got the open tabs, bookmarks, and an initial set of history items from the other devices -- but no new history items will sync. Seems like a bug but can't confirm with only one data point. Gotta take a look at the Other Half's devices later to see. ¯\(ツ)/¯
I did try turning off Safari syncing in iCloud settings on the iPad, and chose not to "keep" any of that data when doing so. I confirmed that the history/bookmarks/tabs were wiped, and then turned syncing back on on the iPad. I got the open tabs, bookmarks, and an initial set of history items from the other devices -- but no new history items will sync. Seems like a bug but can't confirm with only one data point. Gotta take a look at the Other Half's devices later to see. ¯\(ツ)/¯