Seeing body progress but lifts aren't going up-- time to switch up routine?

[rsc07c]

Hey guys. I started lifting in September of last year and have been pretty consistent, I think out of those 8 months I've only taken 2 weeks off. Considering how much of a stick I was before I've seen a decent change in my body during this time, and was really happy during the first 6 months because I was consistently being able to increase the weight I was doing. But in the past couple months my bench press (dumbbells) has kind of stopped going up and its frustrating lifting the same thing every time and not being able to not increasing the weight. Whats wierd to me though is that at the same time my lifts are staying the same, I'm continuing to see improvement in my physique. Do you guys think I've "plateaud" and should change up my routine, or continue with what I'm doing if I think I'm seeing progress even though I've been doing the same routine for 8 months?

Cliffs: think I've plateaud but I'm still seeing improvement in my body despite lifts staying the same, should I continue with the same routine I've been doing for 8 months or change it up?

Current routine:
Monday: chest
Tuesday: legs
Wednesday: back
Thursday: shoulders
Friday: bis/tris

Thinking about changing it up to this:
Monday: chest/tris
Tuesday: legs
Wednesday: off
Thursday: back/bis
Friday: shoulders/traps

Thanks for the help.

[AlphaPole]

Its not the routine brah, its the nutrition.
eat moar simple.
If you are certain its not the nutrition, post what you are consuming during the day so we can look at it.