Have you received the Android 12L / One UI 4.1.1 update? This is the key update for the Samsung S8 tablets at present and has been rolling out this month.
The development of Android 12L (for larger screens) has been following a parallel path to Android 12/13 (mainly phones). Understandably, Samsung has looked to use Android 12L for its flagship tablets.
This article (https://www.sammobile.com/news/samsung-devices-eligible-for-upcoming-android-13-update/) suggests that we are on the list for Android 13/One UI 5. My guess is that phones will be the priority and we will receive it in a few month's time.