2 overlapping screen-space camera uGUI canvas fail to display TMP

Unity Engine
,
1

repro:
2 screen-space camera canvas C1 and C2, each one using a separate UI camera U1 and U2
U1.depth > U2.depth
in such configuration all uGUI stuff such as textmeshpro will fail to display on U2

2

not only TMP, uGUI image and imagerow as well

3

it shows in the scene view, just not in the render camera that’s referenced in the canvas