It looks like I'm affected by this problem, with a very similar net-misc/networkmanager-1.14.4 configuration:

[connection]
id=eduroam
uuid=87727d7d-e931-4c63-a066-7188b3a6a410
type=wifi
permissions=user:root:;

[wifi]
mac-address-blacklist=
ssid=eduroam

[wifi-security]
group=ccmp;tkip;
key-mgmt=wpa-eap
pairwise=ccmp;
proto=rsn;

[802-1x]
altsubject-matches=DNS:eduroam.hes-so.ch;
ca-cert=/usr/local/share/ca-certificates/eduroam-HES-SO_CA.pem
eap=peap;
identity=[obfuscated]
password=[obfuscated]
phase2-auth=mschapv2

[ipv4]
dns-search=
method=auto

[ipv6]
addr-gen-mode=stable-privacy
dns-search=
method=auto

When trying to activate the "eduroam" connection via nm-tui, it loops several time through scanning -> authenticating -> associating -> disconnect, then ends up asking credentials, and the story goes on – see attached log, kernel says "wlan0: deauthenticating from 78:ba:f9:d8:8a:a1 by local choice (Reason: 3=DEAUTH_LEAVING)".

Apparently something in the WPA2 Enterprise EAP / 802.1x module broke from v2.4 to v2.6, but I can't test the former version as it's no longer in tree.