Yeelight LED Monitor Light Bar Rechargeable YLODJ-0027 Flickering

I use a lamp connected to a desktop PC via a USB input. After buying the lamp, a few days later the lamp began to flicker unpleasantly. When connecting the cable to the mains charger, the flickering stopped. When reconnecting to the PC, the flickering continues.
Please tell me why, when you connect the power cable to the USB port of the computer, the lamp starts to flicker?
There was no flicker for several days of operation.

Thank you very much

Because the voltage and power of computer USB sockets are usually insufficient to support the normal use of lamps, just like using a computer USB socket to charge a mobile phone will be very slow.