Direct Connect (DC) is unpredictable. Many aspects can affect it. One moment you can DC & mins later you can't. lol
If you can browse a person then there's a reasonable chance you can dc with them. But not guaranteed. It's easier to browse than dc. Good idea to have chat enabled to help with dc. I use DC & browse very frequently to help me reconnect to some files or downld more from that source, etc. I find it very handy.

If you have a friend you wish to DC with then why not send each other magnet links via email. Once the magnets start downlding you can browse them & probably dc with them also. And chat of course if you both have this enabled. To create a magnet link, go to your LW Library window, select a file from your shared folder. Then right-click (mac users control-click) the file. Choose Magnet details for file. This will open your browser & you can make a note of the magnet (use one next to word Magnet!) Copy this to an email & when your friend receives it, they can copy the magnet into their browser (they should have LW open at the same time.) Then LW will start downlding the file.