Losing Premade while queuing in 3v3 ranked

It's a very new weird bug that seems to appear since the patch v3.3.18.36375 or the patch before.
How to reproduce :
- prepare to queue 3v3 (Europe Server)
- invite a pre (see other bugs with invalid GP difference, but not related to this bug)
- let the pre join
- queue
- At some point i find a game but my pre is not in, and they are "looking for players 3/6 " -> I lost the pre on the road with no warnings or queue interruption
- Note, they never clicked cancel obviously, or that wouldn't be a bug

2 observations :
- It's reproducible 100% of the time with me hosting for my pre (5 tries over multiple days)
- It's never happening when pre is hosting for me. So this problem is asymmetrical somehow.

Setup Question :
2 - Windows (for both)
3 - DirectX (for both)
4 - See above
5 - No video or screenshot to provide for now
6, 7 - N/A