Hmmm, well, my node is also for 433 MHz, RAK4631(L), just like the one of the other thread: Need help with range issues using Meshtastic on RAK4630 modules on 433MHz frequency - #4 by Crichton
Could that make a difference? We would not expect that. So maybe someone else who is using the RAK4631(H) model could do a serious power measurement. I don’t have modules for 866 MHz here…
But it should be easy to detect if there is a 28 dB change of power or not! Simply by watching the rssi reading in a fixed antenna configuration.