Some info here Sharing same SPI with LoRa/LMIC and Epaper
Worth doing a search on there first 
From a fault finding approach I would get your none RFM95 SPI device working on its one first, on its own SPI bus (ie not the one RFM95 is on) and make sure that code is stable, then look to bring that code into the normal working LMIC codebase.
I have to ask, ‘bee counter’?