You may have to supply more information about your Mac and its operating system.
For interim use, you may try to create a wi-fi hotspot; but that isn't a real answer.
Your phone is accessing the internet via wireless from 'eduroam.' That in itself isn't
all that helpful. There may be an issue with settings in the mac, connectors, modem
(wired or wireless components). And the iPhone could be accessing this differently.
5 common 'mac' wi-fi problems and how to fix them:
https://www.macbookproslow.com/how-to-fix-wifi-issues/
What have you tried for troubleshooting? I've dozens of bookmarks, each can only
be posted here rather manually, titles do not automatically follow the link in ASC.
If your Mac doesn't connect to the Internet over Wi-Fi - Apple Support
https://support.apple.com/en-us/HT202663
How to Troubleshoot & Fix MacOS Mojave Wi-Fi Issues
osxdaily.com/2018/11/19/fix-macos-mojave-wifi-problems/
Connecting to eduroam using Mac OS X - IT Services
https://itservices.usc.edu/eduroam/mac/
Have you tried a new user account in Mac for troubleshooting that aspect? This is
one of many topics that have no activity. (I've lots to do offline. And no help here.)
Is some aspect of the Mac system set to time-out? Is the main internet fully wi-fi?
Are there any local devices that may pose interference to the Mac internet? Can
anything on wi-fi go by wire instead? (If not already.) Sorry to not be of help here
& all this does is put the discussion ahead of the cue, in hopes it gets momentum.
