Changing the A320 and B787 COM/NAV/ADF standby frequency with SimConnect Events do not work

My SimConnect client can read the COMs active and standby frequencies, but the SimConnect Events to SET or INC and DEC do not work.

Well, they work so that I can the correct readings back via the correct Variables, but the airplane seems to have an internal frequency placeholder. How to get access to that is the problem.

Any idea how to make this work via Sim Connect?

I haven’t found any LVars for this.