Do you look different, to yourself or perhaps a significant other who takes interest in such things? If so, the theory is likely correct. Muscle is heavier. I hit a floor weight-wise at 205, but my body has continued to change while at roughly that weight -- my neck and waist measurements, in particular, are still falling, albeit much more slowly.
Based on lifestyle, calories in and calories out, I've seen my body settle into certain sweet spots. 250 (too much), 238 (I was there I kid you not for 8 months!?), 220 (3 months) and now 205 (been a year -- I think this is the new normal). You are at one of yours. You need to decide whether a more lean / muscular 233 is what you want. If it's not, then do more -- and focus on more cardio and less anaerobic. This can be as simple as spinning in a higher gear.