It must be an issue with the way your work network is configured. Possibly some form of security filtering which needs validation with your device?
Its quite common on open networks, your device has to be authorised, otherwise it will not be given an IP address, so you get no Internet access. Speak to your work IT people.
It could be that you have to scan a QR code, to register your device on your work network. The code probaby represents the hardware MAC address of your mobile device and its IMIE number.
Others may have already done that, and simply forgotten about it, or it might be that this is a new feature, and all the other users` devices have been registered beforehand.
Scanning a QR code, does make it easier for IT to keep a track of devices, as they can be kept electronically, and devices can be removed from the network when people leave.
Also visitors can scan a code, and be given temporary access for just a day.
Cannot suggest anything. The only thing that might make sense with the numbers you mention, would be the wifi band. 5Ghz or 2.4Ghz, but if you have connected to their 2.4GHz wireless network, then it should work.
Its possible that you were connected to the 5GHz network on your old phone, when you last visited, that would present a different MAC address to your work network, which does not tie up with your name. Or it could simply be that they cannot link that new phone, with your name.
If you have visited the site before, with your old phone, then you would probably have to ask your IT people to delete your existing old record, and allow you to register your new phone against your name.
Its essentially an IT problem.
Have you tried "forgetting" the network and restarting your phone and then remaking the connection.
It would be very unusual for a company network not to have a password/passkey to enable access to its network, even if it is available to guests/members of the public.
There should be some sort of wireless passkey/password that you need to enter to get access. It should offer the place to enter the password if you tap on the Network name in the WiFi settings. If it is not apparent there you may be offered a "landing page" if you open a browser.