Items I had equipped in survival disappeared after drowning

So i was playing Minecraft bedrock on a slightly laggy world and was mining around in a empty cave since it was under a mooshroom biome. I then went through a sampler cave entrance, mined some iron and entered a water cave that opened behind it. I mined a little in said water cave and was in a weird compact part with my air running out. I proceeded to try and mine my way up to create an air pocket but didnt make it in time. Having a bed above on the surface is ran back down into the area and grabbed my stuff. I swam into an air pocket to regain air and looked in my inventory to see i had none of my Armour and my pickaxe I was holding got deleted too. Not believing that actually happened I swam back to get my stuff, mined around when I couldn't find it and ran up to the surface to see if it clipped through like an eye of ender… none of It did. I had an iron helmet, pants, and boots, and a diamond chest plate, including my iron pickaxe, that all were just kinda deleted from the world. I also apparently can't upload the video I took of this issue for some reason so that's another problem ig.