Stalled generally means the original host of the file is not online or has removed the file from shares or WireShare has given up trying due to multiple efforts which may occur if both the host's upload & upload queue slots are busy. Another common reason these days (as compared to 10+ years ago when 80+% of hosts used static addressing) is the host's ip address is dynamic & has changed. Some hosts have highly dynamic addresses which means they may change one or more times a day or so.

Always the best thing to do after WireShare has settled down (after the first 5 or 10 mins) after connecting to the network is to do fresh searches for each of the individual files. This will bring in fresh host results and if the file-hash matches the incomplete file it will hopefully go into queue mode or restart downloading depending upon how busy the host's upload slots are.

There will be hosts with different numbers of upload slots. Possibly as low as one or two which means it can be difficult to win a slot if that host's upload slots are tending to be busy or pre-occupied for a long time due to very slow upload speeds. Such slow uploads might include large video files for example.

Whilst it is possible to use the 'Try Again' command for each download, or wait for WireShare to do its periodic recheck to see if the hosts of the relevant incomplete files can still be found, WireShare relies on the addresses it knows shares the file. If those addresses have changed then such techniques will not work. With over 80% of the network now using some form of dynamic addressing, this is more common a problem these days.

Keep in mind the network is somewhat dynamic during a session as you connect to different peers over time and hosts come online or go offline. So do the searches every couple of hours or so as the results might find some relevant results not seen earlier. There's also a reasonable chance of search horizon shifting slightly over those periods.