Hi jaakko224,
We appreciate you reaching out to us.
We’d like to gather additional details that may help us be in a better position to assist you.
Would you please tell us what type of WLAN system you are using? Is it a Wi-Fi network?
If you are using a Wi-Fi network, please make sure that you are using the recommended Wi-Fi settings to prevent interruptions.
Recommended settings for Wi-Fi routers and access points - Apple Support
If you are getting a ”Sync paused due battery saving” message even if the battery is full, please check your device's battery health.
iPhone Battery and Performance - Apple Support
If you are experiencing sync interruptions when using cellular data, please check for a software update and make sure that you are running the latest version of iOS and iPadOS.
While it isn't inherently assured that an update will resolve the issue, updating to the latest software version for your device can help isolate potential software issues.
Kindly secure a backup and update.
- How to back up your iPhone, iPad, and iPod touch
- Update your iPhone, iPad, or iPod touch
Then, check if you have to install a new carrier update.
- "Make sure that your device is connected to Wi-Fi or a cellular network.
- Tap Settings > General > About.
- Follow the onscreen instructions to install your carrier update."
You can use the article below as a reference.
Manually update your carrier settings on your iPhone or iPad
Take care!