Hello Iphonagragh,
Thanks for clarifying this for us as it allows us to be on the same page as you.
Since you're seeing that the login information is correct, let's confirm that you have the latest iOS and iPadOS versions installed on your devices. If an update is available, this could clear up the message you're seeing if the devices aren't able to communicate. We'll include steps below to help with backing up and updating your devices, and you can also view additional details here: Update your iPhone or iPad - Apple Support
Update your iPhone or iPad wirelessly
1. Back up your device using iCloud or your computer.
2. Plug your device into power and connect to the internet with Wi-Fi.
3. Go to Settings > General, then tap Software Update.
4. If you see more than one software update option available, choose the one that you want to install.

5. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.
If you have the latest updates installed already, confirm that you have a passcode enabled on both the iPhone and iPad. Depending on your Apple ID security preferences, this may be required and could be a cause of the message appearing in Settings. If you need assistance with setting up a passcode on one of your devices, check out the steps here: Use a passcode with your iPhone, iPad, or iPod touch - Apple Support
We hope that's able to help with clearing this up. If not, contact Apple Support directly to check into this with you in more detail.
Have a great day!