I got the following circuit and with the help of this website I know that R2 = 10k, R1 = 200R, R3 = 1M.
Vref is 4,1V, I apologise for the bad writing.
The problem is that when I connect R1 to R3 and the photodiode + pin, the voltage that usually is 4.56 and above drops immediately to a few 300mV in that node.
The Op-Amp is the LM358p (Datasheet).
What am I doing wrong? I assembled the circuit as it is in the schematic, but I can send a photo if needed.