mushroom help please

so ive been having issues with my mushroom rock basically forever and i really want this fixed. the tank has been running for about 6 months, i ran through my cycle for a month and then started to place corals, the first picture here is the mushroom coral rock about a week after putting it in the tank, but after that first week, they have shrunken and moved off the rock to other locations and frankly are doing horrible, im not sure what the reason for this could be.
im curious to know how affected mushrooms are by nitrates, since then i have been struggling with keeping my nitrates low, it is getting better as of recently because of changes i made to the system and maintenance.

please advise on this, other than nitrates, all of my parameters are good.
my nitrates at one time were up to 80 ppm but that has come down drastically and is now at 15-20ppm and still coming down, im hoping that once i get this fully fixed and down to 0 will they start to be open and happy again?

param:
78.9 degrees
ph 8.0
calc 480
0 nitrite
0 ammonia
etc all good other than nitrates..

here are the pics
first is from a week after placing corals
second is recently after about 4 months

 

15-20 nitrates isn't bad really. What lights are you running? Shrooms do best in low light/flow and will move looking for more suitable digs

 

im running boostled par30 bulb, 2 royal, 1 reg blue, 1 neutral white, 1 white

its on a small 10gallon cube
the weird thing is that the mushroom that is in the most light is actually the one that is doing the best... the ones that are more hidden are very very small now instead of what they originally were like.
my nitrates at one point spiked to 40+ but are now at the 20-25 range and continuing to go lower, so my question is really how much are mushrooms affected by nitrates? will i see them start to come back big now that the nitrates are lowering to their original when they were first put into the tank?