SiK Radio Heartbeat /Connection issue after upgrade

I am running 3.6.10 and i had a set of 915 as a test that were working fine with only very small range.
Took out of my other Quad that runs 3.6.10 the radio that were 433mhz 500mw and i simply decided to run the firmware upgrade since they were pretty old.
The upgraded to 2.0 and since then no matter what they cant connect.
They connect to eachother and they are both found in MP, but they simply dont connect to my cube.
Tested ECC on and off, tested oppresend on and off and nothing seems to make them want to want. tried also RFD 1.9 and nothing seems to work as it should.
Any ideas?

Got a screenshot of your radio settings in MissionPlanner?
Also check the setting for RTS/CTS on that serial port is disabled in AC.

I tested also a variety of other firmwares.
Checked that BRD_SER?_RTSCTS was Auto and switched to disable to make sure.
I switch back to 915 and all works fine.
What i do notice is that on there format is set to 26 while on another 433 (holybro mini) and 915, its set to 25. Could this be the reason?

I’m unsure about that Format value, I’ll research it.
You can turn off ECC though. Error correction is not needed for data that is constantly changing, and it will slow down your data rate significantly.