solution found

If you want to use sysmon inside PL together with external MUX, dont use Vp/Vn to connect output of external MUX.
This is because Trenz-Modules have RC-LP connected to this input.
You can use any Vaux instead of Vp/Vn.
When using banks 47, 48 (TE0808) or banks 46, 45 (TE0807) you would face the problem that Vivado GUI does not allow to activate the sequencer and average on some channels.

This is a bug.
You can workaround this by not using Vivado-GUI, but .tcl script to create Vivado projects (my favorite) or activate these channels by SW after building hw-description.