Chad is generally seen as fairly stable in the Sahel, however, with the Sudanese civil war continuing in the east, illegal gold mining and Libyan smuggling in the north, as well as the IS Sahel province expanding around the Lake Chad islands, there is increasing instability. We won't even get into the growing risk of civil war coming from the Central African Republic and South Sudan, but they will add more pressure.
The fact that their own generals now refuse to suppress local communities is indicative of the growing problems they face, especially from areas bordering Darfur, as the governments' tacit support for the RSF causes divisions in the Zaghawa accord.