Prefab instantiates at the wrong (seems like only y) position.

EDIT 2: IT BROKE AGAIN ONCE I TRIED USING 2019.3.0b7 AND ONCE I WENT BACK TO .0b6 AGAIN IT DIDN'T FIX IT. WHAT THE F***.

EDIT: TO ANYONE SEEING THIS POST, THE PROBLEM WAS SOLVED BY USING THE BETA (as of this post) 2019.3.0b6 VERSION OF UNITY.

Although performance is significantly worse in this version (constant frame drops), it is better than letting the project rot.

The title basically says it.
I've been stuck on this issue for like a week now, and I am really desperate to solve it...

It would be very helpful if you would look at my Reddit post on the issue as it already has a lot of information, including a video showing the problem.
I don't mind using a workaround, as long as it works honestly, I just want to get this out of the way and continue with my project...

The post: https://www.reddit.com/r/Unity3D/comments/dimq5h/instantiate_puts_object_in_wrong_position_almost/

Thanks in advance for any help, it's much appreciated!