It sounds to me like there just may be a chance it is faulty.
But you sure can spend a lot of money on swapping parts without a hands on tech on location with every day experience to diagnose it.
You have to make a decision if you are willing to continue to invest money into this problem blindly or is it worth it to get a 2nd opinion.
I see many times that my customers spend the money they want to save on a service call
on parts and never find the solution until they call me to their home and end up coting themselves more.
I do appliances
And I learned too late in life that when I have some thing in my home that i'm not sure about I do not do it myself unless I'm ready to throw money into it.
And i'm frugal so after 50 years of do it myself in other fields , calculated the money I wasted and now I call a plumber or roofer.
My fridge is more than 10 years old and I plan on a new one if it goes any time in the future.
I will not fix it even though I can.
Its costing me more electricity than the newer energy star refrigerators that pay for them selves in a few years.