Lora nexus ttn downlink

Hi everyone,

I have a couple of lora nexus boards from Ideetron and I would like to use downlink. I have tried their example and I am unsuccessful, I saw there was an issue raised in github. I tried changing the value of the register to increase the delay time from 0x1F to 0xE0 on line 89 of the RFM95_V21.CPP.
I would like to stick with the Ideetron implementation because of the memory size used as compared with the Lmic version. If anyone has successfully managed to get downlink working on the lora nexus kindly help me out