I've said it before and I've said it again: You can't build a conspiracy around something which happens regularly and naturally.
The reality is that backmarkers occasionally go for fastest lap if they have nothing to lose. The reasons are various: Because they have nothing better to do, because they want a bit of media attention, because of glory or for personal reasons (Ricciardo might have driven his last race, and he wanted to stick it to the Maccas). Magnussen went for it at Singapore as well (although he might not have if it wasn't for the puncture). Stroll attempted recently as well if i recall, but was too slow. It's not a rare occurence.
Other people have also provided examples of drivers helping friends. Alonso has also helped Max in the past, likely for no other reason than he wanted to stick it to Hamilton.
Fact is sometimes teams help or hinder each other - across the entire grid that is. And since it happens between all the other teams, it is also gonna happen with RB/VCARB. There's also plenty of examples of those two teams getting in each others way. You can't ignore every time it happens to other teams, and then press the alert button every time it happens between the two teams who happens to be co-owned. You need supporting evidence.
And just to be clear: Natural distrust and dislike of the fact that Red Bull has two horses (or well, technically four) in the race is completely fine! There's nothing wrong with that!
However, claiming that the teams are deliberately working together - without any reliable evidence whatsoever - is not. It's a direct accusation of cheating without any evidence to back it. And that is what OP did here - and it's completely unacceptable in my book.