Are you detangling during the wash and condish or waiting until you towel dry? The fact that you're losing hair afterwards might suggest that you may want to try detangling earlier in the process.
I have 4B hair and experienced the same problem -- wash and condish goes great, no problems, until I towel dried and started rollersetting and run into issues detangling and I went thru all kinds of "detangling" products (poos, condishs, leave-ins, etc) to no avail, until I switched the detangling phase to earlier in the process when my hair is fully saturated with condish and I take my time and comb condish thru until fully detangle and then rinse (If deep condishing, apply and put plastic cap/heat for however long and then comb thru just before rinsing OR if in hurry, I just slap on condish, comb thru, rinse and move on). My hair remains detangled and manangeable every time, regardless of what products I use and I've concluded it's not so much the products as it is the method and timing, at least for my hair - it's like butter no matter what I use, which I found kinda interesting. . . hmmmm, it's not what products I use, its the method . . .like the old saying, it's not what you say, its how you say it. . . (if that analogy makes sense!).
Anywho, HTH!