Your feedback network is not good. You have a voltage divider set up (R5 and R4) prior to the compensation network. To be honest, I don't even know what this will do to the network. The way to set the voltage without messing with the compensation network is to place the voltage set resistor from the Feedback pin of the regulator IC to ground. This method assures that the ac component is not affected (in the small signal ac analysis, the feedback node is shorted to ground which removes that resistor from the analysis completely).
In regards to the compensation network - I would suspect that this system is not stable. I would suggest the following changes:
R5 - short this with a jumper
R4 - leave open (do not populate)
R1 - change to 12.1 kOhms (1%)
R2 - change to 215 Ohms (1%)
R6 - change to 12.1 kOhms (1%)
C3 - change to 15nF
C4 - change to 330pF
C5 - change to 33nF (please take note of the n's and p's)
Now place a 3.01k (1%) resistor between Pin 4 (VFB) and Ground.
These values made some assumptions regarding the inductor DCR and output capacitor ESR, but it should provide a much more stable system than what you have now.
I would suggest the following read through to get a better understanding of stabilizing voltage mode buck regulators...
https://www.electro-tech-online.com/custompdfs/2006/07/tb417-1.pdf