Update 11/4
I’m downgrading this to Minor because I can solve the problem temporarily by restarting UEFN, and because a part of why my lighting initially looked worse in UEFN than UE5 was because of a mistake in my master material, which was my fault.
Original Post 11/3
Since the last update I’m having a lot of bugs with the Skydome Device. 
I’m using a cel shader post processing volume I created, and these skydome issues affect me with or without the cel shader.
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Lighting /color intermittently looks different in the Editor than it does in Live Edit and gameplay. I’ll get the settings looking the way I want them to look in the editor, but then in the game it appears like the settings are still at the default settings. Or the lighting in the editor will bug out and get weirdly saturated (I’ll explain that more next) while the lighting in Live looks fine.
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Sometimes after I do something like move any object or save a change in a material graph, the skydome effect will suddenly become blown out and saturated, even though the settings don’t change. Fiddling with the settings doesn’t fix it. This also happened once when I deleted the Skydome and did Ctrl Z to undo and bring it back. When I quit and restart UEFN, the Skydome has returned to normal.
Weirdly Saturated in UEFN editor (My cel shader is active here. I didn’t capture a screenshot without the cel shader, but it did look weird without it too):
Looking normal in Live Edit (also with the cel shader):
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Sometimes when I’m changing settings, sky gradient colors do affect the ambient light, even though I’ve unchecked that box. Like, to test it I changed all of the gradients to black, or pink, and all of the scene’s lighting was affected. Sometimes this doesn’t happen though - it’s intermittent. This makes it very hard to know what my settings actually look like. Actually - in retrospect, this last point might be the key to the first two points - maybe when the lighting looks different in the Editor vs Live, or when it suddenly gets super bright, it’s because the sky gradient suddenly starts or stops affecting the light. I’ve experimented with turning all of the sky colors white, which would produce this effect.
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Hiding the skydome in the outliner by clicking the eye icon does not work. The skydome effects stay the same.
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Not Skydome related, but changing the time of day in Experience Settings doesn’t affect the lighting in the UEFN editor view. I think this is known but it’s annoying.
This skydome stuff has been really frustrating for me, because for the past couple of weeks I had been building my plant shop environment in UE5 to avoid some UEFN bugs, and when I started importing my assets over to UEFN my art looked so much worse. Even with a lot of skydome tweaks, and even when the skydomes were working properly, it was hard to get a nice basic indoor lighting. In UE I just left most lighting settings on default and it was fine. My cel shader looked great and my custom materials looked true to color. I feel like in the future other creators who want to move art from UE over to UEFN might feel similarly frustrated by the skydomes.
Are there plans for creators to be able to bypass the skydomes someday and create our own custom lighting, like using a Directional Light actor? The skydomes appear to be geared toward outdoor lighting, and I’m working on a chill indoor environment. We have Point Light and Spot Light actors but the attenuation on those is kind of small, like, they fade out when the player moves away.