Partner hasn't received Deadlock invite

[RedRabbitVT]

I sent my partner the Deadlock Playtest invite, as well as 3 of our mutual friends. The 3 mutual friends got their invites BEFORE my partner did. It's officially been over 48 hours, I contacted Steam Support and was told they couldn't do anything, we kept checking his emails, and the playtest invites page on his Steam account, and still received nothing. The 3 mutual friends even sent the invites to him, and still there's nothing. I don't know if his account invite was bugged, but it's strange that all 3 mutual friends got their invites within the span of minutes to a couple of hours, yet my partner STILL hasn't gotten his as of typing this. Is there any dev that could help?

EDIT: I fat-fingered in a few sentences, it was 3 mutual friends, not 4. Sorry, changed it now.

EDIT 2: The account user is this https://steamcommunity.com/profiles/76561198121351386 if that helps the Dev team if they see this. Much appreciated!