Sweet Zz stunted and funny colorage close to the middle.

new growth being yellow and shorter internodes hints at too high of P or K. There are other possibilities i'm sure. could be a runt, but seems like a normal looking plant to me. The nodes are quite close together. Raise light 2-4 inches and see what happens over next 5-7 days. if you are in a soilless substrate and you calculate your ppm for P/K et al, P should be 30-60ppm give or take and K should probably be 200 or less. YMMV, as local enviorment will impact how much it can metabilize per day. soil is much more complicated in this regard, but if soilless, some simple math would help rule out possibilities. (6,0 ish pH. I'd err on high side rather than low side of 6 as you drift much below 5,8 you end up with ph-related problems) a well balanced 1,3 to 1,5 EC mix is ideal starting point for soilless. soil is a total unknown and you'll have to learn to ride that bike yourself through experience. using same products will breed familiarity. take soem notes of when you supplement nutrients etc etc. My best guess... raise light 2" and see how it responds. if the new growth continues to be light green, then almost certainly nutrient related. My recent weeks had a similar issue. I was testing higher levels of P and after 6-8 weeks from sprout i started to get light green new growth. My context was clear and easy to deduce. I dropped back to previous levels and within 1,5 irrigations it was abating. New leaves were no longer starting light green. check out my google drive share folder on my GD main profile - click my avatar. sort comments by date and it'll be at the top. leaf chart is excellent to keep handy. i have a ppm spreadhseet if using dry nutes and handle specific gravity of thos labeled w/w%, a dli table, a vpd table etc.. useful reference material. Or, google image search for it. you can download but cannot edit my files i shared. the spreadhseets were all made with oppenoffice calc and contain zero macros. very simple stuff with only formulas. instructions in A1 for the ppm spreadsheet. (less useful for soil, but can help deduce what needs to be supplemented over time and if tracked, makes it very easy the next cycle to reproduce)

Your pot looks a bit too wet, unless you just fed before the pictures and even then it looks like your whole pot is soaked, the plant is still pretty small at this point, don't have to soak the whole substrate. Some of the issues can be from overwater/feed That other issue in the middle of the leaf I have no clue have never seen anything like that. It does look like physical damage a bit 🤷

its hard to see properly.. to me it looks like something has fallen down onto the plant?