Log shows as using data when I’m asleep and the phone is connected to the WiFi

I have been checking my date usage and have discovered I have used a lot of data at times when I’m in bed asleep! It’s always around the same time 1am. The phone is connected to the WiFi could anyone help with this please

JillC I had this on my Android phone.

The culprit was power saving settings, specially 'Sleep standby optimisation' which cheekily dropped my wifi overnight and switched to mobile data. So I turned it off and that sorted it.

Thank you I will try and find the equivalent on iPhone

Solution for iPhone:

Here is how to lock your phone onto Wi-Fi overnight and stop the data charges:
1. Turn Off Cellular Data for iCloud Backups
iOS is programmed to run heavy backups while charging overnight. If your Wi-Fi dips for even a second, it will ruthlessly push that massive backup over your cellular network.

1. Open Settings and tap your name at the top.
2. Tap iCloud → iCloud Backup.
3. Toggle off Back Up Over Cellular. [1]

2. Block Cellular App Updates
Prevent the App Store from downloading large updates over your data plan while you sleep.

1. Go to Settings → App Store.
2. Under the Cellular Data section, toggle off Automatic Downloads.

3. Disable Wi-Fi Assist
If your home Wi-Fi signal fluctuates overnight, this setting secretly switches your phone to cellular data without telling you.

1. Go to Settings → Cellular (or Mobile Data).
2. Scroll all the way to the very bottom of the screen.
3. Toggle off Wi-Fi Assist. [1]

4. Turn Off "Low Data Mode" on Your Wi-Fi
If Low Data Mode is accidentally turned on for your home network, your iPhone will disconnect from Wi-Fi during sleep to save bandwidth.

1. Go to Settings → Wi-Fi.
2. Tap the "i" icon next to your connected home network.
3. Ensure Low Data Mode is toggled OFF. [1]

5. The Ultimate Overnight Fix: A Shortcuts Automation
If a software glitch keeps disconnecting your Wi-Fi, you can force your iPhone to turn off cellular data automatically when you go to bed.

1. Open the built-in Shortcuts app and tap the Automation tab.
2. Tap the + (plus) icon to create a new automation.
3. Select Sleep (when bedtime starts) or Time of Day (e.g., 11:00 PM).
4. Set the action to Set Cellular Data and change it to Turn Off.
5. Create a second automation for the morning to Turn On Cellular Data when your alarm goes off. [1]

To find out exactly what used your data last night, go to Settings → Cellular and scroll down to the Cellular Data list. Which specific app or system service shows the highest data usage?

Thank you I will try these options

So will I thanks, JayH83