does not accept verification code tells me to re-enter password followed by code where?

trying to activate my 2 older apple tv boxes dozens of times after change of internet provider. they both worked perfectly before and both are current operating systems. every time my apple id and correct password the set asks me to the six digit code after re-entering password I click ok and the screen then asks to enter apple id and password the problem is where ? in the past ( a year or two ago) an idiot-proof screen would appear with six boxes into which you typed the code. not now none appears and if you type in the code immediately after your correct password in the same box you are told incorrect password and are back at the start apple id box. in the last 36 hours of frustration I have tried more than a dozen attempts on both with no success. please help this old man!