2D Tilemap brighter in viewport

Hello,

I started working with 2d textures and tilemap in Unreal and I have this weird issue in my viewport (and when play) where tilemap appear brighter than the texture.
I deleted all the lighting and started with a blank project. On some forums they say to check sRGB but it was already checked (and if I uncheck it it’s even brighter)
Auto exposure is also deactivated, and lighting was rebuilt.

I just don’t understand where the problem is.