The reason why clowns seem weird on the hosting issue is many people do not realize their clowns probably have not been given the type of anemone as they would be found in in the wild.
When you give a clown a non natural host match, it often takes much longer for the clowns to recognize it.
I find this to be super common as probably the most popular clowns usually are occs or percs, (probably thanks to Nemo), and the most popular anemone would be BTA's, as they are easiest to come by, and often quoted as most forgiving.
These are not natural host matches as found in the wild, so they may find it eventually, just often takes longer.
Another safe trick to help is put a flashlight over the nem as lights are ramping down, often the clown will be curious to the lighted area, but bottom line it's usually best to give a natural host match, or exercise patience, do not force close proximity, it can be harmful to clowns that have not adapted to sting cells