What do you mean by bad and from 5 to 6 now depends but the quality difference isn't that huge so is normal that some of the 5 stars to perform better, is not like you are comparing a 3 stars or a 4 stars with a 6 stars.

Another aspect now is that depends a lot on your opponents quality too. If you have strong opponents they might not perform super great.

My advice is to follow them, give them few games... At the time you made the post you could had only 1 official game so let them to play more. Friendly games are always tricky and is hard to make a personal opinion.