The wifi does have to be compatible so maybe that's the reason.
Eg https://support.apple.com/en-il/HT203302
"If you're using an iPhone 12 model or later, turn on Maximize Compatibility.* Then try connecting your devices again to your Personal Hotspot."
There are compatibility things between wifi devices. Most of it depends on the settings. Manual config will cause more problems over them just automatically detecting and doing it for people. In some cases they don't automatically make adjustments. In others they may have set the hardware to simply not be backwards compatible and nothing can be done besides buying a different device on either end.