The clone tool works fine but the result isn't as good. I always worked with the heal tool and it has always worked fine. The heal tool looks better because it adapts the texture, with the clone the result isn't as beautiful.
Also, when using the heal tool, the global exposure changes a bit randomly (it's visible on the short video in the previous message). It's not the case with the clone tool, so cloning works perfectly fine and i guess I'll use it waiting for the problem to be resolved (hopefully it will someday !).
I tried with a different camera, and the heal tool works better. I don't have those black holes anymore, but the global exposure may change a bit (but that's not a big issue).
Maybe it's important to note that sometimes the pics are perfect in Lr, but the black holes appear after export on the jpg.
So, the Sony A7IV raw files don't work (the dng either), on the A7III it works better, except about the exposure.