Hi rjurd,
Thank you for reaching Microsoft Community. I'm sorry to hear about this weird behavior that you are having on your Surface Laptop 4 when charging. Definitely, this is not normal but we'd like to ask for some details first regarding with the set up.
- Which Surface Laptop 4 configuration do you have? AMD or Intel? 13.5" or 15"?
- Is the power supply that comes with the Surface being used or you are using other third party power supply?
- Is the power connected directly to the outlet or is it connected through a power strip? If connected through a power strip, try connecting it directly to a wall outlet.
- Have you tried charging it on a different location like at the office or on a coffee shop? Does the same behavior occurs?
- Are any other peripherals or accessories connected to the device while charging?
Kindly run these steps below also on your Surface then observe if the same behavior still occurs:
1: Run Surface Diagnostic Toolkit
See: Fix common Surface problems using the Surface Diagnostic Toolkit (microsoft.com)
2: Check for Windows Update
Go to Windows Settings > Update & Security and select Check for updates
Make sure all updates need are installed including Optional updates
3: Update drivers and firmware
Check what is the current OS Build of your Windows version by going to Settings > System > About.
Go to Download driver and firmware for Surface, choose Surface Laptop
Then click the link next to Surface Laptop 4 then click Download on the next page.
Choose the .msi file that matches your current OS Build and click Next.
After downloading, run and install the .msi then Restart.
4: Run System File Checker Tool
See: Using System File Checker in Windows (microsoft.com)
Hope this helps.
Kind regards,
Marrion