double checking what you’re calling your “collection”?
would “where your hash collects” define it?
It does for some. Not all. because: cannabis!
FWIW: Luna calls that bit their “distillation column” 
(see: It puts the Cannabis in the tube, & then it walks away again).
both @Swet254k @GroovyOctopusLabs seem (to me) to be assuming you mean “the tank in which your recovered solvent collects”.
In which case their responses are spot on.
if that’s NOT what you mean, we need to explore further.
thawed fresh frozen == water which can cause problems when you make ice with it.
more heat to your evaporator should speed recovery (increased pressure). as should more cold on your target solvent tank. if that isn’t what you see, then a pressure sensitive blockage between your evaporator & solvent tank might explain it. not sure how you cause one of those with ice, but I certainly wouldn’t rule it out.
what you got between your evaporator and your solvent tank?
pictures?
is this today’s run only?
or have you seen this before?!?