Unable to connect to guest WiFi network

Since the latest update to KDE Plasma I am unable to connect to a public guest WiFi network. This network does not require any passwords but uses a captive portal for me to accept their terms. I have been using it for many months now without any issues. It appears that the latest updates broke something.

All I see are the following notifications:

How can I diagnose what is going on?

This is what I see in journalctl output:

Jan 24 12:53:56 replicon NetworkManager[7615]: <info>  [1769277236.3273] device (wlp113s0): Activation: starting connection 'MC-Parks-Guests' (aef59f8a-e7d1-4cbf-bf73-1317c6877f3b)
Jan 24 12:53:56 replicon NetworkManager[7615]: <info>  [1769277236.3278] device (wlp113s0): supplicant interface state: completed -> disconnected
Jan 24 12:53:56 replicon NetworkManager[7615]: <info>  [1769277236.3278] device (p2p-dev-wlp113s0): supplicant management interface state: completed -> disconnected
Jan 24 12:53:56 replicon NetworkManager[7615]: <info>  [1769277236.3284] device (wlp113s0): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
Jan 24 12:53:56 replicon NetworkManager[7615]: <info>  [1769277236.3285] manager: NetworkManager state is now CONNECTING
Jan 24 12:53:56 replicon NetworkManager[7615]: <info>  [1769277236.3287] device (wlp113s0): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
Jan 24 12:53:56 replicon NetworkManager[7615]: <info>  [1769277236.3289] device (wlp113s0): Activation: (wifi) connection 'MC-Parks-Guests' requires no security.  No secrets needed.
Jan 24 12:53:56 replicon NetworkManager[7615]: <info>  [1769277236.3289] Config: added 'ssid' value 'MC-Parks-Guests'
Jan 24 12:53:56 replicon NetworkManager[7615]: <info>  [1769277236.3290] Config: added 'scan_ssid' value '1'
Jan 24 12:53:56 replicon NetworkManager[7615]: <info>  [1769277236.3290] Config: added 'bgscan' value 'simple:30:-70:86400'
Jan 24 12:53:56 replicon NetworkManager[7615]: <info>  [1769277236.3290] Config: added 'key_mgmt' value 'NONE'
Jan 24 12:53:59 replicon NetworkManager[7615]: <info>  [1769277239.3508] device (wlp113s0): supplicant interface state: disconnected -> scanning
Jan 24 12:53:59 replicon NetworkManager[7615]: <info>  [1769277239.3508] device (p2p-dev-wlp113s0): supplicant management interface state: disconnected -> scanning
Jan 24 12:54:02 replicon NetworkManager[7615]: <info>  [1769277242.3846] device (wlp113s0): supplicant interface state: scanning -> authenticating
Jan 24 12:54:02 replicon NetworkManager[7615]: <info>  [1769277242.3846] device (p2p-dev-wlp113s0): supplicant management interface state: scanning -> authenticating
Jan 24 12:54:02 replicon NetworkManager[7615]: <info>  [1769277242.3890] device (wlp113s0): supplicant interface state: authenticating -> associating
Jan 24 12:54:02 replicon NetworkManager[7615]: <info>  [1769277242.3890] device (p2p-dev-wlp113s0): supplicant management interface state: authenticating -> associating
Jan 24 12:54:02 replicon NetworkManager[7615]: <info>  [1769277242.4217] device (wlp113s0): supplicant interface state: associating -> completed
Jan 24 12:54:02 replicon NetworkManager[7615]: <info>  [1769277242.4217] device (wlp113s0): Activation: (wifi) Stage 2 of 5 (Device Configure) successful. Connected to wireless network "MC-Parks-Guests"
Jan 24 12:54:02 replicon NetworkManager[7615]: <info>  [1769277242.4217] device (p2p-dev-wlp113s0): supplicant management interface state: associating -> completed
Jan 24 12:54:02 replicon NetworkManager[7615]: <info>  [1769277242.4219] device (wlp113s0): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
Jan 24 12:54:02 replicon NetworkManager[7615]: <info>  [1769277242.4222] dhcp4 (wlp113s0): activation: beginning transaction (timeout in 45 seconds)
Jan 24 12:54:47 replicon NetworkManager[7615]: <info>  [1769277287.8566] device (wlp113s0): state change: ip-config -> failed (reason 'ip-config-unavailable', sys-iface-state: 'managed')
Jan 24 12:54:47 replicon NetworkManager[7615]: <info>  [1769277287.8569] manager: NetworkManager state is now CONNECTED_LOCAL
Jan 24 12:54:47 replicon NetworkManager[7615]: <warn>  [1769277287.8572] device (wlp113s0): Activation: failed for connection 'MC-Parks-Guests'

And the last thing I see in the GUI before the failure message appears is this:

This is working again. The last thing I did was to move /etc/NetworkManager/NetworkManager.conf to NetworkManager.conf.bak file, restart NetworkManager and move the .bak file back to .conf. I don’t know if that’s what did the trick, but I am just glad that it is working now.