I think that the One UI 2 is a bit heavy because after I update my phone, it lags a bit and somehow overheat. Is that normal or the S9+ can't support the new update?
after update the phone need time to indexing the apps as such you will experience lagging. After few hours or days depends on how many apps installed in your phone, it will back to normal/smooth. It's advisable to wipe cache partitions after the update.
