Gateway will only let me reset the PW for 1 of the bandwidths

I set up NOW internet service this morning and went to change the gateway PW.  I wanted the PW for both bandwidths to be the same.  It let me change one but when I went to change the other, it said it was "invalid". Spent all day trying different PW's and getting told by chat bots where to go with no success. Really need to get this straightened out. This internet has been really goofy. Not sure this is going to work out. Help would be appreciated.