I was thinking that it must think you’re new to weights so it keeps you at a low rep count and it might increase soon there after. I mean it always moves me higher even when some workouts seem difficult for me.
Yup-particularly if you are in the middle part of this Journey
One thing I would say though, is 5kg is quite a light weight to be using. As a guide we would recommend using 7-12kg dumbbells for male users , although please vary from this if there are personal factors that mean even these weights would be too heavy.