how can i fix this issue?
Hi TeaTone!
This bug could be caused by a many things. First of all check id your light point is not too close to the walls.
Second check your material settings. Roughness should be a texture or any 1 component vector with values between 0 and 1 (greater than 0). Specular Power should be anything above 1 (the common practice is to use 32.0 as a default value)
Hope that’ll help!