what
PLreef said - look for insects. Tough to deal with now as she is well into flowering. If you find eggs under the leaves, try to mitigate by
* can you take it outside? If "yes", put the plant on a table so that you can spray water underneath. And you have a better look under the canopy. Blast those leaves with a good spray to wash away eggs. Blast hard enough to swing the leaves but not hard enough to blow them off of course. Use a sprayer, I don't mean blast with a garden hose. Then bring plant back inside.
* cut off leaves where you find eggs
* take a soft cloth and dampen it with alcohol and wipe down the leaves, both sides, then spray with water
* wipe your pruning shear blades with rubbing alcohol before and after pruning
* at night right before the lights go dark and the surface of the soil is dry, cover the soil with 1/8" of diatomaceous earth
* place foil around the base of your plant, light will bounce off the foil and onto the underside of the leaf
Many insects, like aphids (not saying you have that but you might), hate citrus and a homemade insect spray using orange or lemon peel can help mitigate. Now this will sound crazy but it's true - aphids hate bananas - cut up a banana peel into very small slices and create a ring around the base of the plant. Remove in a couple days. Many insects love the color yellow (aphids, gnats) and some growers put a yellow bowl under the plant filled with water. Insects then drown.