Grundig G8 radio lock button instructions (buttons not working)

If none of the buttons work, the radio is locked - you will see the small "key" symbol. Normally we just keep down on the "key symbol" lock button 2 seconds to unlock the radio, but there can be an issue which I explain in this video
Owner manual https://data2.manualslib.com/pdf5/105/10492/1049140-tecsun/pl300wt.pdf?3947beaa25f208e8850c47d0f0d547a7