No internet when downloading from a USB stick! How so?

It sounds a bit strange, but the internet on my new laptop breaks when I want to transfer data from a USB stick to the laptop.

I bought a new laptop and now I have to transfer the data from the old computer. I use a USB stick for this. If I plug it into the appropriate input on the laptop, I still have Wi-Fi connection. But if I start the data transfer, the Internet stops immediately!

Who can help me please?

Coincidentally is this a MacBook? I also have this one USB stick that interferes with the WLAN when I use it…

Probably happens if the USB devices are not well shielded

I'm not sure how the data transfer should work with you:

A USB stick for what? Memory stick, WLAN stick or Bluetooth stick.

If WLAN stick, then why on the laptop? He has something internal, doesn't he? Does the PC have a WLAN connection or a LAN connection to the router?

USB stick just for data transfer! I copy data from the stick to my new laptop and the internet connection is lost!

Perhaps the laptop is so busy that nothing else works. Otherwise I would not know what one thing should have to do with the other.