Sounds like it could be your soil--both ground and in the container. What's the soil like? Palms like a soil rich in humus that drains well. Something definitely wrong (I think my robustas must put out 2-3 new fronds per month at least. Mine are in large tubs and I water every day.)

May have some root damage there,in which case it will
take a while to grow new roots...assuming there isn't
some fungal infection.

Soil is very heavy clay here in the desert. Seriously like concrete trying to break through it. But I added probably 30% mulch/compost to it before planting. It's the same soil as all the other palms that are doing good. Do I need to fertilize or water less/more?

Maybe I didn't dig the hole deep enough? I loosened it probably close to a foot beneath the root tips. I may dig it up to see how water-logged it is. Should you let these palms soil dry out between waterings, or keep them somewhat damp?

Any ideas on what I should do? What kind of water and fertilizer schedule do you guys use?

Just give it another year.. it will probably start to pick up.. some palms go into a funk if roots disturbed at planting and can take up to 3 years to come out of it.

So it seems to finally be pushing up a new frond. Should I continue to water twice a week, or do more/less? What about fertilizer?

my mexican fan palm is doing the same thing and i planted it in soil amended with about half gravel and half native soil (very rich fertile soil) but I think my palm is growing even slower than yours! It has yet to make any progress!