Fireworks and Elytra stopped working

So it might just be a problem with my computer, but when I played with 2 of my mods, epic enchants and xp storage, fireworks no longer give a speed boost when using elytra. You can still use them when flying, but they go straight up. This means you can place them in the air, which is not normally possible. Please help me know what caused this because no vanilla data got changed, so I have no clue what happened.