Time to Change Something?

I’ve been having pretty good progress with weighted pullups for a about 3 months now. I haven’t changed anything about that one excercise, because honestly I haven’t had the need to until now. Today I did back, and in my log for last week I had 70x5, so 70 pounds on the dip belt five times. I tried to do my usual progression and do 6 reps, that way I could bump it to 75x5 next week, but I was stuck at 5 again.

My body weight is going up (I’ve actually gained 5 pounds in the last 3 weeks somehow), so I guess that could be a reason, but even so, should I go ahead and tweak my weighted pullup workout a little bit? I just need something that I can use to punch this plateau in the face and continue moving forward. How would a month of going for a slightly lower weight for higher reps be?