Is that an older leaf, if so, maybe acclimation issues. If it is an ephiphyte and not terrestrial, and is in soil, not something airy like bark...then a number of things could be hurting it, like trace elements commonly found in soils/tap water.

An anthurium i purchased off the discount rack in the spring expressed similar symptoms after i brought it home, but after repotting into an airy mix and understanding the watering schedule more it perked up and is on the road to recovery...but i don't know which species either of them are.

the above is a hybrid of A. andreanum. and they are epi's and need fast draining soil, but prefer organic matter. that is they just love long-fibre sphagnum moss with scoria/bark/perlite.
they also need to be warm, when air-temp is 65F - the roots are at 60F - at this point they usually start yellowing the leaves.
so, keep them where it is at least 70F. and no cool drafts, no standing near cold windows either. they are super-tropicals.
pull the root-ball out of the pot carefully and see if it's damp. moderately moist is what they need.
soggy will cause leaf decay, spots, dark tips,etc, especially at cooler temps (below 70F).
they also do well in just pure coir-chips (cococoir is from coconut shells) and/or coco dust (it is also called coir peat) or combo of both.
common name for this plant is 'flamingo tail'. they'll need very good light to continue blooming - early or late sun in winter is a must. unless you're south - then same, but thru sheers or dappled, moving sunlight.
when temp/light conditions are met they will bloom/grow continuously year round. the top leaves should get larger.