Hi. I filed a bug report the other day with the same title, and I think I know what caused it. Maybe, but I think the cause is "rocket fireworks". As I mentioned last time, I tried different ways of flying after that, and when I flew with rocket fireworks, or when I accelerated, I took damage. So I tried using them at shorter distances, and apparently the fireworks effects were coming from the player at different times. With damage determination, of course. And when I checked my inventory, I found that the durability of the elytra had not decreased, while the durability of other equipment such as head, leggings and boots had decreased. I don't know if this will help you, but that seems to be the cause of this bug, so please give it a try. I'll be waiting for the bug to be fixed.

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