Sorry to hear that, although I never used my 105 for streaming, I was relieved to read that it still functions as a player. I have been concerned about losing this unit if it ever fails. I use mine primarily as a BluRay, Cd Transport and for SACD 2 and 5.1 surround.
That said, I use the Bluesound Node for streaming and it does a good enough job on its own and even better with an external DAC. If you prefer the sound of the DAC of the Oppo, you can take the digital out on the Bluesound in the digital in on the Oppo and you’ll be back in business.
It does seem odd that streaming is the only function that has failed. Have you checked the Ethernet connection, re assigned your Wi-Fi if so used? And I am sure you have tried unplugging the unit, press each face plate button while unplugged for a capacitance reboot, to see if self corrects?