There are times when the sound effects and other sounds are mixed with dialogue into the original audio, so the English dub doesn't have it. This makes it feel empty and lifeless.
In the course of sound editing, everything possible is split apart:
Spoken dialogue gets its own set of tracks.
"Good" noises caught on-set (usable footsteps, paper shuffling, etc) are called Production Effects (PFX), and those get their own tracks. The dialogue editor has to dig those out of the dialogue tracks and separate them into their own tracks. The dialogue editor also cleans out any "bad" noises.
Foley, like footsteps or horse hooves, get its own set of tracks.
Voiceover (ADR) gets its own tracks.
"Futz" meaning stuff that's coming through a speakerphone or something, gets its own tracks. That's all created in post production from either ADR sessions, or wild takes on-set.
"Hard effects" like explosions or other things that the post production team create, or otherwise pull in from outside of what was shot on-set get their own tracks.
Background sounds get their own tracks.
Music obviously gets its own tracks.
The M&E mix for international re-recording is generally the following:
PFX
Foley
Hard FX
Backgrounds
Music
That way whatever team is overdubbing the foreign language tracks can work with material that doesn't interfere with what they're trying to do.
Part of the "uncanny valley" effect that you're getting is that international overdubs have to be done in a sound booth, and then reverb/delay has to be added to make the dialogue sound like it's actually being spoken in the environment you see onscreen. Faking that experience through reverb and sound design is actually a really, REALLY difficult thing to pull off convincingly. There's just no substitute for all the tiny cues our ears perceive from the nuances of what's actually recorded on-set.
That's why it so often sounds fake. Because it is. And like Mr. Plinkett says, your ears might not have been able to tell that something was wrong, but your brain could.
I think it's because the language being spoke in the original doesn't translate perfectly to the other and the lip movements might last longer or less time than what it would be in english. Therefore, people are having to say things that aren't exactly natural to make sure they're still speaking as long as the lips are moving. If that makes sense.