Thanks for posting and welcome to the Bose Community. I am sorry to hear that you are experiencing some issues with your Soundtouch system and would love to look into this further for you.
Can you please let me know if this issue happens across all sources as well as if it happens at certain volumes? I would highly recommend that you reset the system via turning off your product and disconnect the power cord for 30 seconds.
Please update me on the result of this and answers to the questions above.