Microsoft & Safari Log in Difficulties/Unsecure Connection on Server

First of all, iPadOS 17.7.10 is current for your iPad. You should update to this version.

The issue that you describe is a problem with TLS/SSL - these protocols being used by your iPad and the services with which you are experiencing difficulties secure the connection. The potential causes are many, but may be an issue with your internet connection.

Are you using a domestic network/internet connection, or instead a business or educational network connection? If the latter, TLS/SSL may be blocked or using deep-packet inspection - both of which will break or inhibit the secure connection with the intended server resources.

Perhaps a long shot:

Do you have a 3rd party VPN installed, even if you are not using it? If so, delete the VPN profile in Settings/General/VPN & Device Management/VPN, then restart your device. Don't just turn it off; delete the profile. If that fixes it, you can try reinstalling VPN, but probably shouldn't.

You mention both logging into a Microsoft account, and adding a Microsoft account. Where are you trying to add your account? Adding a school account in Settings > General > VPN & Device Management, for instance? Or adding a mail account? Or something else?

In addition to the above VPN questions, are there any browser extensions, any school student-monitoring tools, or any ad-blocking apps installed?

riannachesleigh wrote:

I don't use a VPN. Just plain, old WiFi.

To clarify some potential confusion in the phrasing, you don’t use a VPN, or you don’t have a VPN installed?

Because VPNs that are installed — even if not currently in use — can cause issues akin to this.

riannachesleigh wrote:

I've been trying to add and directly sign in my Microsoft account in Microsoft apps like Copilot, Microsoft Edge, Word, etc. but it always shows "No Network Connection" after I input my Microsoft email. I tried signing in my Microsoft account in a laptop and Android phone, and it worked, so I assume that my IPad is the problem.

Okay.

Are there any VPNs, browser extensions, any school student-monitoring or proctoring tools, or any ad-blocking apps installed?

riannachesleigh wrote:

I don't have a VPN installed.

Okay.

Are there any browser extensions, any school student-monitoring or proctoring tools, or any ad-blocking apps installed?

Does the iPad have the same problem with Microsoft when connected on a different Wi-Fi network?