Thanks a lot for sharing your experience
I had reached a similar conclusion
I tried to put in the oven the modules that failed, but only a few were "fixed"
I have already successfully used another type of modules mounted in China at a lower price than the individual components, and I assumed that they could reach that price because they manufactured millions of modules
But in the case of the GY-521 it seems to be of very poor quality, it struck me that I did not find any comments on forums about these bad modules
I am evaluating redoing my PCB to directly mount the original MPU6050
Thanks again for your help