I had tried that earlier but I'll show you how it worked here.
This is with AE turned off and the manual exposure slid to 100. I still have the problem.
Are there other settings I can look at? Since you got it to work without adjusting anything in the model, it must be a settings issue. (I've only had Enscape for a few months and YouTube only teaches so much)
it's not the settings so much (except AE) rather the lack of light energy because they lights that are placed are on such low values.
Turn AE off - in my example I set it to 60
Then increase the values of the lights - notice how the spheres are bigged in my screenshot - this means they are brighter
Another option to tackle this scene on the whole, which is more efficient is to use some self illumination for the "glowing" things.
Turn off AE find the materials of the flames
Change the flame from "generic" to Self Illumination
change the colour and tint to a nice warm colour and adjust the brightness until the flames look nice.
You could do the same for the lava
That will get you something like this
Now that isn't casting a light onto out seats etc , you could increase the exposure a little more, but there is a good chance this simply isn't pumping enough light and we may introduce noise- self emissive lighting isn't usually enough. So lets place a key light.
Place a single sphere light , paint it a similar cooler and adjust the brightness until it looks as required
Now we've achieved a similar effect with a fraction of the number of lights - lights are expensive to use in enscape, so we really want to use as few as possible wherever we can.