Super overlooked, but try it out! I know we're all super excited to try the new stuff, but try do a fresh REGULAR restart (NOT a factory reset) of your phone after installation.
I seen a couple of people here who said that the quick settings in the notification tray were not allowing them to swipe over to the next page and the overlap of the UI with double dates and time as well was showing up. I had those as well and thought maybe restarting it may fix it, and it did! No more lag for me as well and things seem to be working pretty normal.
The galaxy app booster and the memory guardian helps a ton after restarting, you can find them in good guardians. All of the things in there help especially the thermal guardian.