Both Max Verstappen and Sergio Perez struggled at the Marina Bay circuit last weekend, with neither driver making it out of Q2 as the squad also suffered its first defeat of the season.
While its issues over the weekend were compounded by set-up mistakes, its chief engineer Paul Monaghan also dropped hints about 'inherent' problems being a factor too.
Asked if this was something that had been there all season, Monaghan responded: "Sort of. Without elaborating, it's difficult to explain, but you're kind of on the right thread."
Asked by Motorsport.com to explain what Monaghan was alluding to, with the RB19 having been so dominant, Red Bull team boss Christian Horner has pointed towards the car not being strong in short corners.
He says the first evidence of that was delivered at the Monaco Grand Prix, where Verstappen was pushed hard by Fernando Alonso for pole position and the race victory.
"Certainly, if you look at a race like Monaco, Fernando's lap there was phenomenal," said Horner. "It took something extra special from Max: I think he hit every barrier in the last sector to take that pole position, which is obviously so critical there.
"So, at Monaco, there were already signs that street circuits were a challenge for us. Azerbaijan as well was more of a challenge. I think that there have been some short corner circuits that have posed some issues for us."
Horner said that confirmation of its short corner problems means Red Bull can give some thought to addressing it for 2024, but he was equally aware of how difficult it was to deliver a car that was quick on all types of tracks and turns.
"It's something that obviously we'll be looking to address going forward because you have to have a car that can compete across a broad spectrum of circuits," he said. "And I think actually that's where RB19 has been pretty strong.
"But it's obviously finding that balance of how much you weigh in which particular area. Because, as we're seeing behind us, circuit to circuit, different cars are suiting different venues.
"So to have one that fits the whole envelope and covers the whole envelope is very, very tricky."
The underlying characteristic of the RB19 means that, even if Red Bull went back to Singapore knowing what the problem was, it probably would not automatically dominate.
"There's never a silver bullet with any of these things," he said. "It's a combination of how is your interaction with aerodynamics and mechanical set-up? It interacts, obviously, with the tyres and the layout of the circuit.
"I think we'd be probably a little different to where we started, but there's a lot of lessons that we've taken out of that."
