Sounds like it may have been a case of ‘Sympathetic Resonance’
https://en.wikipedia.org/wiki/Sympathetic_resonance
Something in the refrigerator, possibly the compressor or another part of the system, induced some resonant frequency in another appliance and together they would vibrate in sync until one or the other unit stopped whatever it was doing.
Just a guess..................
Well, that’s something to consider. Will muse on that one a bit.