MBA 2020: WiFi (eduroam) disconnects every 30 minutes

My IT department and I have tried a lot of things, yet the issue remains unresolved. Here's some more information:

• MacBook Air 2020 (Intel i5)
• Since the day my university replaced the old eduroam access point in my building with a new one, the MacBook gets kicked out of WiFi every 30 minutes.
• As my uni has installed this new type of new access points in other buildings now, I can confirm that this problem exists with all of them.
• In buildings where they still have the old access points the connection is perfectly stable.
• An older 12 inch MacBook is not affected by this problem, so clearly this is some kind of interaction between the new access points and the MacBook Air.
• The problem occurred under Catalina 10.15.3, persisted under 10.15.7, and is still there in Big Sur 11.0.1.
• In Catalina, I often (but not always) had to manually reconnect a dropped WiFi connection. In Big Sur, the MacBook automatically reconnects within a second or two. (Still, when in a video conference, the short D/C means that audio and video freeze for a while, which is annoying. Also, if I use a VPN, the VPN gets disconnected during the short D/C).
• My uni's IT department has worked for days to find the issue, with no success. They now installed a LAN cable (!) in my room, so I have a stable connection for video conferences.
• The IT guys have also informed me that Cisco's “Optimized Roaming” feature, which forces devices to disconnect under certain circumstances, is deactivated on all access points.
• The problem occurs in 2.4 and 5 GHz networks and on different channels. 
• The country codes of all access points are correct.

Here's what I tried so far:

• SMC/PRAM reset has not resolved the issue
• removing/adding WiFi in System Preferences has not resolved the issue
• deleting all network-related .plist files has not resolved the issue
• changing the JoinMode in the command line airport tool has not resolved the issue (I tried all of them)
• creating a new user has not resolved the issue
• booting in Safe Mode has not resolved the issue
• deactivating Little Snitch and the built-in firewall has not resolved the issue
• updating Catalina from 10.15.3 to 10.15.7 has not resolved the issue
• upgrading Catalina to Big Sur (11.0.1) has not resolved the issue
• moving closer o the access point (or in my case: installing an additional eduroam access point right above my desk) has not resolved the issue

I'm out of ideas. It's 2020 and there is no chance of getting a stable WiFi connection with a brand new computer on a university campus in one of the world's most developed countries.

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