iPhone does not automatically Auto-Join a known network

The iPhone always joins all of the known networks, those I have provided a Password. But a certain network, at work, will never trigger an Auto-Join response from the iPhone. I always have to: 1) choose the network, 2) provide the password. By the way, this does not happen with my MacBook Pro 16" 2021 M1 or even with the previous MacBook Pro 15" middle 2015. Regardless of the current MacOS, they always automatically connect to this Wi-Fi network. The iPhone 11 Pro in question never connects to the network, regardless of the iOS. In Fact, my previous iPhone 8 did not connect to the network either. I did transfer all of the set ups and data from the old iPhone 8 to the relatively new iPhone 11, so I am not sure if I also transferred "something" that prevents the iPhone from Auto-Joining this WiFi network. As a further piece of information, other iPhone do join this network automatically.... I would very much appreciate any suggestion. We have obviously restarted the iPhone, restarted the network and selected "Auto-Join" this network, etc..., but that does not produce any positive outcome. Thanks!