I paid $1000 for a phone and why do I keep seeing ads in stock apps like weather, Samsung daily, Galaxy store?
Download addguard. It blocks all adds in all apps and in your internet browser.
I will give it a try but still it should be default on a $1000 phone.
Go to settings, accounts, then click on your Samsung account > privacy > disable the cutomization. Also, in the settings menu of themes store make sure customization is turned off in settinfs there as well.