[Need help] Start position in VR in editor is correct but not in packaged build (4.26)

Hello! I’m having some issues with a VR project. I’m setting up the start location of the Player, and everything seems to work fine in Editor. However, when I package the game, the start location is completely wrong.

Here’s the situation in Editor. Floor level, indicated by the red sphere, and height looks fine.

And here’s the packaged version, without any changes. The height and floor are completely wrong.

I have no idea what is going on. I just set the Start Location like this (because otherwise it would spawn slighlty higher, creating issue with the floor):

and there aren’t fancy stuff in in the blueprint. I’m just setting the Set Tracking Origin to Floor and I’m using and HTC Vive. Nothing else, nothing more. Does someone have any idea why there’s this difference when playing in Editor and in packaged builds? Thanks for your help.

Ok, apparently, the issue is that the packaged version of the game seems to use another Game Mode that isn’t either the Default one or the one I’ve set for the level. Any idea why it’s not doing what I’m asking it to do?

Just for some context: one of the game mode is meant for people in my team without a VR Headset, so setting up the starting location is different then the one for people with a VR Headset. Thus the reason of the issue exposed precedently.