Safari Profiles and Tab Groups are missing

My Safari Profiles and Tab Groups have disappeared. I'm running MacOS 26 (MBP) and MacOS 15.5 (iMac) as well as iOS and iPadOS 26. The Tab Groups and Profiles where synced via iCloud.

I noticed the disapearance after I switched to a new iPhone 17 Pro. The mandatory software update right out the box was the only software update on my devices that I did recently.

I already tried a restart and of cause checked on all devices. I have not tried re-enabling the profiles in the safari settings yet, as I fear that might overwrite previous ones.

[Edited by Moderator]