Red Bull got a big win at the United States Grand Prix last weekend, with Max Verstappen winning sprint race, pole position, and Grand Prix and getting dangerously close to McLaren, but also suffered a setback and were fined €50,000 for violating safety regulations. It did not concern Verstappen nor teammate Yuki Tsunoda, however, so no point deductions, only a monetary sanction for the team.
The sanction happened because a member of Red Bull technical staff had entered the grid once it had been cleared, and this person failed to listen to the marshals who asked him to leave the area, due to obvious safety reasons. "Hindering or delaying the process of closing the gates before the race start must be considered as an unsafe act and therefore a significant penalty to the team is warranted", the stewards say.
The reason why this person was in the grid at the time was, apparently, to remove a strip of duct tape stuck in the grid, that would have helped rival driver Lando Norris for McLaren to better position his car in his grid box.
An astute trick that isn't penalised by FIA, despite Red Bull's clear intentions with tampering with McLaren's work. These markers with duct tape in the grid are used by the drivers as reference points to optimised their positions, due to the very limited visibility from the cockpit. In the same way FIA doesn't forbid using them, FIA doesn't penalise teams that intentionally remove them.
As such, the sanction was only because of this staff member from Red Bull, whether willingly or not, did not listen to the marshals and entered the grid to perform his action when the gates had been closed. "In order to prevent any reoccurrence, a portion of the financial penalty is suspended", FIA added, so Red Bull will only pay €25,000 if at the end of the season they don't commit another infraction.