New tree fern mount growing blue-ish mold.

[AndreaK]

It has been several years since I've posted anything. I am getting back into growing after a long delay. I lost the majority of my orchids after a move, followed by a house fire.

It's a new tree fern mount. It came in a pkg. of 2. The first mount was placed in a terranium in April. It has shown no signs of mold. This 12x12 mount was split between 3 plants two weeks ago. There was no signs of mold until this week. On Tuesday, November 12, it was watered and fertilized. It seems to be staying wet longer with the temps in the low 70s to high 60s. I have a ceiling fan and two small fans, for circulation, in the orchid room(10ft×12ft). Should remove the plants, discard the mounts, and treat with a fungicide? If there is a way to keep the mounts, that would be preferred. Also what fungicide do you recommend? A photo is attached
showing the stage of the roots. It was a bare root Cattleya that was purchased at the Redlands Rare plant festival in October. The 2 other mounted plants have roots at about the same stage.