AUDIO IN Jack does not recognize connection

Hi @davejones7666

Sounds like it may be a faulty audio jack.

Some audio jacks have internal changeover contacts that when operated by the insertion of the audio cable plug, operate to disconnect the BT audio input from the speaker and connect the audio cable input to the speaker instead.

Other types of audio jacks have a single internal make contact which operates to signal the audio controller on the board to switch the audio from the BT source to the audio input source.

I don't know which type is used in the speaker but here's the ifixit Sony SRS-XG300 repair guide that will help to gain access to the inside of the speaker so that you can check if the audio jack is working OK electrically when the cable is inserted.