I suppose that those people who were put in front of a camera post election were likely have been the most enthusiastic supporters who were hopped up on their 'things can only get better' supply. But the red wall was decimated in 2019, when people who had a history and culture built around labour (not all of us, but enough for it to be called the red wall) gave up on the status quo in hope that they'd find a voice in the other guy. And Boris couldn't deliver the manifesto or the on the promises he made. So they spun the wheel again, with Starmer - who offered job creation, low taxes and, err, change - something different. This wasn't an endorsement, it was last chance saloon. The votes came in but scepticism was high and trust was low.
And this is how Starmer started to fall in popularity the moment he hit the ground and the polls for Labour followed after him. Within days this promised change was couched with nasal whistling caveats of 'later, later' and '14 years of Tories' and then along come the u-turns, the game was up and Labour had confirmed their worst suspicions.
It was always a shallow win. There's no faith, loyalty or patience for them. Polls and elections will only tell you who people will or have vote/d for, not their tolerance for them. Not being the other guy isn't going to save you.