Elytra's problem

When I'm in the middle of a trip flying or just moving around my base, the elytra close up and makes me fall on the ground. Most of the times it kill me and I just have to take time picking my stuff back, I've never prove it in the nether or in the end because if that happens I would Lose all my inventory. I checked if the problem was mine but it isn't, I have good connection and I don't push any wrong button. I'm adding a video showing what happens. Please fix it, makes playing so uncomfortable.