I would bet you do not have the type of anemone that your clown would be found in the wild.
I agree any coral is hit or miss, but those of us who spend a fair amount of time in the anemone forum have come to recognize that even clowns that have ignored an anemone for a long period of time, once given the proper sea anemone as it would be found in the wild, host acceptance is almost always near immediate.
The most common issue we see is people buy any ol clowns, typically occs or percs, and any nem they come across, typically a BTA, and then wonder why they never pair up, and BTA is not a natural host for occs or percs