I also have this problem. I am using Roon on a Windows 10 virtual machine inside an Intel i5 host. 8GB RAM given to Roon. Disk is SSD.
When I remove Qobuz, the search is fast. I moved from Tidal to Qobuz when 1.6 came out, and that’s when the problems started. I couldn’t say whether it was the 1.6 upgrade, or Qobuz causing the problem.