Boat Refrigeration - compressor noise

[barold]

I just had a professional replacement of a sailboat refrigeration (evaporator plate and compressor)

It has been running for about 2 days now and there is this recurring sound (like metal squeaking. The tech tells me this is normal and the sound of the refrigerant changing states but my old fridge (same brand - Vitrifrigo) did not make this noise.

Here is a link to the sound:

https://photos.app.goo.gl/gzY1viuqn4HfP8xaA

Is this normal and to be expected? I don't think I can sleep with this noise if it's constantly squeaking like this.

[barold]

Update. the lines were purged and refilled and the noise is gone.