I may be wrong, but I think the network requirements are higher for local files than for anything streamed from Qobuz or Tidal, so this could still be a networking issue.
The only thing I could find that seems relevant is this thread. If you read it through you’ll see that the switches may have been causing problems, so it might be worth seeing if you can change your network configuration to see if it makes any difference. I also seem to remember reading that managed switches can cause problems for Roon, so this might be further evidence that you have a networking problem rather than an issue with your SSD,