Samsung j200gu frp problem

i got one samsung j200gu with frp locked.i resetted using z3x 24.1 ver and it powered on without any problem.i gave back to customer .but next day he again bring the phone with same problem.what he did was downloaded apps from playstore and restarted the phone.but again it came like that.then i again resetted frp and flashed it and hard resetted.then i tried to download some apps using google account but it flopped.same again it went to frp please give aproper solution for this problem.

Thanks advance