There is no easy way to disable auto-exposure on a per-component basis. This is a big source of confusion for people new to Unreal. The work around is to set Min and Max Brightness to 1 or set to Manual and set ExposureCompensation to a sane value of like 10.
We need the option to just Disable or maybe an intensity value like other posts so you can just blend it in and out to eventually off.
This has existed forever but with UE5 it feels like we could do something about it.
Try to toggle autoexposure in the post process volume panel
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-140644 in the post.