Incomplete Paths
 

So far I have tried to understand/find a solution to my problem in other related threads without success. I am modeling flow through a series of grids/bafflers. At the beginning of my simulations I had a problem because I obtained a temperature divergence, I unplugged the energy eq, solved and plugged it again and got rid of this, but then I noticed that even though my values converged whenever I wanted to take a look at the streamlines/pathlines most of them (about 75%) were incomplete. I tried many things, increasing the stepsize, number of steps, solving with a different model, going around the divergence by switching to W instead of V (instead of unplugging energy eq) but there was almost no diff in the pathlines. I then tried improving the mesh a little, adding more nodes and this improved the number of escaped pathlines (to about 50%) I however still have a good amount of pathlines that do not let me rely on my results. Any suggestions? Or reviews on what could causing this problem? Maybe if I could know exactly were to refine my mesh I would be able to add more nodes there, unfortunately I cannot use as many nodes I as I wish I could. Please help.