Problems connecting ring doorbell camera and outside camera to new sky broadband router

We have received a new Sky broadband router working off fibre broadband recently updated by BTOPENREACH.  Have spoken to Ring help but I can’t quite believe what she’s telling me and wonder can anyone confirm.  She says if the new wifi is 5 (it is actually 6  having confirmed with Sky - whatever that means) the doorbell and camera are not compatible and need to be linked to WiFi at 2.4.  Surely this can’t be correct?  Any advice would be appreciated. Thnx