Since our update to Wireless firmware versions MR 25.5 I've had reports from users that their devices are prompting them to sign in to the network every morning.
They report that once they respond to the prompt, they get connected without having to enter a username and password. Splash page retention was set for 30 days, and I've since increased that to 90 days (which wasn't available last time I looked).
Anyone else seeing anything similar?