OFS is a valid state of MQA indication for when a device receives an MQA signal already decoded by a downstream piece of hardware or software. As signals decoded downstream cannot be authenticated in the same manner as the original un-decoded bitstream we use ‘OFS’ which stand for ‘Original Frequency Spectrum’ to show this is still an authenticated MQA stream, and the end point device is rendering correctly, based on the Original Frequency Spectrum.
If your audio source is a downstream application with an MQA decoder, such as Tidal or Roon. The application may have a switch to disable the MQA decoder and passthrough the bitstream signal to your endpoint device.
Decoding in hardware or software, splitting the process or performing both in the same device, will not give any audible difference, as the decoding and rendering information is the same, based on the bitstream content. In essence, the system is working correctly and MQA content is being received and rendered correctly if you can see ‘OFS’ indication.