While Pico doesn't officially support "rolling back" software, it is possible. Here is everything you need to know about a without spending a dime. Why Downgrade Your Pico 4 Firmware?

You should enter a black screen with Chinese or English text (Recovery Menu).

(Optional) For a permanent fix, some users block the Pico update servers via their home router settings. Conclusion

Copy the downloaded update.zip firmware file into that dload folder. Turn off your headset completely.

On your PC, open a command prompt and type: adb sideload [filename].zip . Wait for the progress bar to reach 100%. Step 4: Finalizing the Downgrade