OK. It seems I have done everything wrong with this plant. Or this plant is a problem child. I took the problem up to the _ _ _ _ _store where there are some true horticulturists (they can teach anyone to think). This cymb. has spider mite, scale, a fungal infection and it was sun burned. If it had a hang-over you might think it had been on a Jamaican holiday.
The damage done is there for good on existing foliage. It's going to be an ugly plant for some years to come. I"ve tried two stores looking for Keltane. No luck yet. Using H2O2 I've wiped down each leaf (the individual scale induced chlorotic spots really stood out then) and douched the potting medium. Then I sprayed every plant I own with Orthanex as a prophylaxis for both the bugs and the fungus.
the sun burn really caught me by surprise. I thought cymb.s liked a lot of sun (my other one , a big box noid) gets 10 hours of direct sun and loves it. This one only got 5 hours a day and I took almost two months of gradually getting it up to that much.