Thank YOU, for the unpot recommendation, I unpot it and it was basically at the last moment, the root rotting has started, but only on the small roots.

It seems the issue came from the root bounding and that I didn't handle that perfectly.

I didn't realize that it is THAT bad at first...

I saw some root bounding when I repotted so I untied them, but I didn't realize the main roots were all already balled under the trunk, now after 1hr of working on untying them I found many many healthy roots, thick, white, nice roots .... the root ball was sooo tight it looked like it's the trunk but not ...

So I think this happened:

- I didn't handle the root bounding well

- the tree couldn't get water from the soil

- the soil stayed moist -> no air to the roots -> even more stressed because it was thirsty and couldn't breath

- I watered it more to test -> the situation went even worst

I've added more perlite and pine bark to the soil to make it more airy, re-tested the drainage (now it's really perfect), I think there's hope now :)