I seem to have exactly the same problem you described, with IoT devices loosing connection to Web apps in Azure at 02:00AM (UTC) on 2025-04-01. I am also in Europe
I have multiple IoT devices (over 3000) trying to connect to webapi on 3 azure web apps. My IoT devices use a modem card (SIMcom SIM7600E) to initiate TLSv1.2 HTTPS connections to my web apps over 3G/4G network.
Do you also use a modem card to make connexions?
I can't access the maintenance notice on the link you provided, do you have more information about it?
Thank you.