Red Bull driver Daniel Ricciardo said he had been "screwed" for the second race in succession after missing out on victory at the Monaco Grand Prix.
Despite securing pole for the first time in his career, Ricciardo finished second behind Lewis Hamilton in changeable conditions following a slow pit stop on lap 32.
Having opted to switch to intermediates while Hamilton remained on wets earlier in the race, Ricciardo - who had re-taken the lead after Hamilton's first stop - was called in again for a set of super-softs.
However, the Red Bull pit crew were not ready for the Australian, resulting in him rejoining behind the world champion, who duly defended his lead to the chequered flag.
The incident followed controversy in Spain a fortnight ago, when a strategy call cost Ricciardo a chance of victory as team-mate Max Verstappen claimed a stunning maiden win.
"I don't even want to comment on the race to be honest, just say thanks for the fans, thanks for sticking out in this weather," said Ricciardo on the Monte Carlo podium.
"Two weekends in a row now I've been screwed, so it sucks, it hurts.
"No idea [what happened] - I was called in the box, I didn't make the call. I got the call, so they should have been ready. It hurts."
"We put ourselves in a race with Lewis that we didn't need to be in and then the pit stop was the pit stop.
"I felt like I was the quickest in all conditions, but second place doesn't show it."
Red Bull advisor Helmut Marko explained to Sky Sports: "We presented it [the race win] to Mercedes. Unfortunately [there was] a lot of misunderstanding and not the right communication. We will investigate and find out but it was a human mistake. We will check it and then we can tell you more.
"I feel really sorry [for Ricciardo], all we can do is to apologise to him."