Pineapple Guava poor performance

I’m in central Florida and have had a few pineapple guavas for 3 years now and while they grew great at first, now seem to be doing poorly.

Some leaves have a slightly fuzzy orange mold on them, and there are dark spots on the underside of leaves. In addition, they’ve flowered sparsely and have not matured any fruit. Mine are seedlings that should probably be grafted over with named varieties, but should I even bother? Anybody having real success with these in Florida?