Samsung has officially confirmed that it is suspending the update of devices to One UI 7, but the reason for this is not entirely clear

Samsung has officially confirmed the suspension of the rollout of the One UI 7 update based on Android 15.
Here's What We Know
The decision comes a week after the update started rolling out for some flagship models such as the Galaxy S24 series and the Galaxy Fold 6 and Flip 6 models. A company spokesperson said that the One UI 7 rollout schedule is being updated to ensure the best user experience. However, the exact reasons for the delay were not disclosed. He also promised that the company will provide an updated One UI 7 release schedule soon.
Earlier, it was reported that Samsung smartphone users from South Korea who received the One UI 7 update started complaining about problems with unlocking the devices. It was also discovered that the Protected Folder in the new One UI 7 interface has some vulnerabilities. Probably because of these, and possibly some other reasons, the distribution of the update has been suspended.
Meanwhile, millions of Samsung devices remain on the previous version of Android, adding to user dissatisfaction.
Source: android authority