Ok I finally receive my last item to the OSMO which was my X5 adapter but the problem is I can't rotate the gimbal securing ring to the lock position fully, it stops in between the unlock & lock position??

Same here. Can´t lock the osmo with the locking ring. Seems to be a lot too tight. What can i do?

Me too. I've torqued as close as I can and it works fine.  Since there's also the screw-in mount there's no chance it's gonna befall off.

I've contacted DJI and they sent me a RMA, so what it appears is that they have a bad batch.

Just curious. Has anyone with this problem tried adjusting the small allen screw in the front of the lock? I can't imagine what else it's for other than setting the snugness. Mine is working fine so, sorry, I'm not going to bother it. lol

Sorry about the issue.
If it's really tight, please contact your dealer for a replacement.
Any further feedback would be appreciated.
Thanks.