Looks like either nitrate, potassium deficiency, or maybe something else. I highly recommend you use root fertilizer tabs for the swords you have there. Sword plants are quite the heavy-root feeders, so they would really benefit a lot from tabs, if you provide them with it. Good luck.
20 gallon - Sulawesi Golden rabbit snails/Japanese Trapdoor snails/RCS/Marbled crayfish tank
55 gallon - Rainbowfish Dutch scape low-tech planted tank
250 gallon - Community Tiger Oscar/Red hook silver dollar/Silver dollars/PB Jack Dempsey/Clown loaches/Tinfoil barb/Roseline sharks/Bala shark Monster fish tank