I am having the same issues with LW 4.12.3 Pro. I've installed on a new PC with cable connection. Searches are fast. Many songs have 3 or 4 stars with numerous users. The file sizes look to be correct for the bit rate. I've had LW fo a long time and never experienced this before.
I can click to download but the entries say "need more sources" or they will try to connect but seldom do. Occasionally one will download but this is rare. I've even uninstalled and reinstalled several times but that doesn't seem to change anything..