Hi.
I made simple DC-DC circut with MP2238, based on Figure 10. from datasheet, and i use supply voltage 12VDC, and output voltage 1,8V. I checked circut corectness three times, and is OK. Circiut is mounted on PCB, and layout is quite well. Output voltage is clear enaught (ripple less than 10-15mVpp). But the problem is with output voltage level. Target is 1,8V. I have several identic PCBs with this circut, but some have Vout 1,8V, and some have … 2,3V. I tried to resolder all, but no effect. So i changed the voltate divider from 100k and 50k, to 100k and 68k, next to 68k and 33k, and voltage no changes.
Can You tell me what may be issue? I will made next measurement and will search for solution, but situation is strange for me 
Thank you in advance. Best regards.