Loco sound issue

I just bought a pennsy legacy  b6sb #525. 2031330. Using cab 1L.  When I am using either of the two lowest sounding horns,  about 50% of the time while blowing the horn I'll hear a little blip sound. Subtle but quite noticeable. Almost sounds kind of like a speaker pop. It will just be a single blip during the horn blowing. I do not hear this during any other audio sounds. Just wondering if anyone out there has this and could see if that's normal? I would hate to pack it up and return it to order a new one just to find out they all do it. This is my first ever Lionel locomotive. All else is MTH that I have. Video attached. Thanks in advance!