Let's check a few things: After LW has been open for a minimum of 30 mins do this test: Bug Report instructions & sample image Is it True/False?

If you have people uploading from you it's normally much easier to maintain good speeds & good search results. I know you're sharing a lot of files.

Another 2 ways to revitalise a download is to do another search for sources. Another is to stop it & reselect it from the search results.

Difficult to know why your problem occurs. It might be the sources have suddenly started shring their upld bandwidth with others, or there may be some interference/busy traffic in between. Or someone's isp if filtering speeds. I'mm sure there's other possible reasons also.