Dell S2722DGM Monitor not as Bright (Luminous) as Advertised?

[Twisted4000]

I just unpacked and hooked up a pair of Dell S2722DGM monitors, which are advertised as 350 nit for luminosity, which is the brightness level I'm going for (both my previous monitors I had, the MSI MAG271QCR and Acer GN246HL, are also advertised and regularly clocked at 350 nit and they're both the exact brightness I like). After turning them on and even setting the brightness to the max setting, and after going through different picture modes in the monitor panel settings, they're definitely not as bright. I even got a pair of Gigabyte G27QC monitors that are clocked at 250 nit (thinking they were 350 nit at the time) and set one of them up side-by-side to the new Dell monitors I got and their luminosity is virtually identical.

I find this odd considering every review and video I watched in these Dell monitors claimed that their nit rate was often rated closer to just under 400 and they're touted as being extremely bright, but as far as I can tell they're actually kind of dim. Is there something I'm missing? Is there some sort of backlight setting I can adjust? Or is this just as bright as these things get despite being visibly and significantly dimmer than other monitors rated the same luminosity? I'd hate to pack up and return these as I'm already doing that to the last pair I bought and am getting a little frustrated. I got these specifically for their brightness along with all the other specs I wanted, but they appear dimmer and simply not as vivid as the previous monitors I had. Any ideas? Thanks in advance.