I looked at the graph of pH for the past few weeks and it never dips below 8.12 and max is around 8.38....

Phosphate and all the other typical stuff is good. I change 10 gallons of water each week. TDS is always 0, etc...looking for something to try. I'm puzzled as to why it is only these two pieces. I have a bunch of other montis and acros that are fine.