Help with being under levelled?

Hello folks,

I am in Sirene (already done the mask axon) and am level 36

Online I’m seeing the recommended level for this area as 50+

Any idea why I’m so underlevelled? I feel like I’ve done a fair bit of optional areas. I’m doing alright like so maybe I shouldn’t care, but I’d hate to end up at the paintress and be like 30 levels below what others were