Red Bull admits it cannot explain radio failures after Verstappen's sign language jibe

Communication between the drivers and the pit wall proved problematic throughout the race in Austin, with Verstappen and Hadjar both experiencing difficulties receiving instructions from their engineers. The failures complicated Red Bull's efforts to manage the race, particularly at a time when strategy decisions were proving crucial.

Speaking to media after the race, Mekies acknowledged that the team has yet to identify the cause of the recurring problems. The Frenchman also admitted that rival teams appeared to be handling radio communication more effectively.

The issue has now affected Red Bull across consecutive race weekends, prompting the team to make finding a reliable solution a priority. However, Verstappen suggested that the problem has been occurring for considerably longer than the last two Grands Prix.

The Dutchman made his frustration clear during the post-race press conference when asked about experiencing communication problems for a second time. Rather than accepting that description, Verstappen pointed out that similar failures had already occurred repeatedly throughout the season.

In Austin, Verstappen struggled to hear Tom Hart, who was working as his race engineer in place of Gianpiero Lambiase. The arrangement was intended to help the Dutchman and Hart develop their working relationship ahead of future races.

The situation was different in Singapore, where Lambiase was unable to hear Verstappen's messages. The pair eventually resorted to coded communication to overcome the problem, but the measures taken by Red Bull since that weekend have failed to prevent further disruptions.

Mekies previously indicated that the team wanted to introduce a more robust solution following the Singapore Grand Prix, although the difficulties experienced in Austin demonstrated that the issue remained unresolved.

Verstappen was not the only Red Bull driver affected in Austin. Hadjar also struggled to communicate with his engineer, experiencing a problem he said was entirely new to him this season.

"Honestly, for me it's the first time it's happening the whole year and I can tell you it's not nice," the Frenchman explained. "I can't hear anything."

The lack of communication created confusion over when Hadjar was supposed to make his pit stop, with the Frenchman revealing that he nearly entered the pit lane at the wrong moment: "I don't know, I just hear some kind of box, box and then I box. I almost pitted at the wrong time once."

His difficulties extended beyond the timing of his stop. Hadjar also revealed that he left the pit lane with the wrong engine map selected, while the decision to switch to hard tyres caught him by surprise. The communication issues added to an already complicated race for Red Bull, with Verstappen also expressing frustration over the team's strategy after finding himself stuck behind Hadjar, who was running a different pit-stop schedule.

The upcoming Mexican Grand Prix could provide Red Bull with another opportunity to assess the problem, particularly as Verstappen's race engineer arrangements continue to change.

Hart is scheduled to work with the four-time world champion in Austin, Brazil and Las Vegas, while Lambiase is expected to return to his usual duties in Mexico, Qatar and Abu Dhabi. The arrangements could also include Imola if other Grands Prix are cancelled.

With both Red Bull drivers affected in Austin, the failures are not confined to Verstappen's side of the garage. Further problems with Lambiase back on the pit wall in Mexico could provide additional clues about whether the underlying cause lies in the car's communication equipment rather than the working relationship between driver and engineer.