403.810 does not interfere with 400.220 MHz. I think I notice the RS41 signal in your waterfall. DFM17 has another modulation type.
RS41 can be viewed here https://photos.app.goo.gl/v8rUTLlDCDaYxUSy2 and if you llike more closeup PCB images that’s no problem too.
In this topic we found Cape Canaveral being the source of the same modulation type in an sat obs