A combination (two or more ) of a chamfer/rounding [Chamfer/Fillet] created by cut extrusion (via sketch) + a chamfer/rounding [Chamfer/Fillet] created by the blend feature (context menu command Create new chamfer/rounding... [New Chamfer/Fillet...] ) can lead to errors and must be avoided (see following illustrations).

Of course, you can switch between different ways of creating chamfers/fillets within a model depending on the installation situation. The restriction only applies to directly intersecting edges.

The combination of ONE chamfer/rounding [Chamfer/Fillet] created by cut extrusion (via sketch) + ONE chamfer/rounding [Chamfer/Fillet] created by the blend feature (context menu command Create new chamfer/rounding. [New Chamfer/Fillet...]..) would be allowed; whether it would make sense remains to be seen.

In this example the Blend feature had been applied first, then the Cut extrude.