I found this issue: Document requirement that textures need to use an sRGB texture format · Issue #6 · Moguri/panda3d-simplepbr · GitHub
It seems to be related to this indeed. But I’m not sure how to address it.
I tried many things regarding framebuffer properties but nothing works. I’m a little bit disappointed because the offscreen rendering looks neat ! Apart from the lighting that makes the robot appears a bit dark it is just perfect 