I have a relatively new computer (less than 1 year old Dell Inspiron 5765 x64) and using Verizon FiOS 1G option for high speed connection. I run a home Minecraft server, with my account acting as host, and a family member is invited to join as a full member when I have the server online.

Ever since 1.8 was released, the family member randomly and frequently logs in only to find himself logged in with his account over 100 blocks above the ground, falling to death in an unknown location, or just randomly dead for an unknown reason, perhaps because of a mob wandering in a well lit, blocked off area that glitched through a wall, even though no mob was around upon logoff. Equipment can not be found as the death appears to either occur far from the logoff location or spawn location, or the death occurs, but time continues and de-spawns held items even though the chunks should be unloaded when the account is logged off (We base about 3000+ blocks apart, to avoid chunk loading interference, and we're both based at least 1000 blocks away from spawn. This makes it impossible to accidentally load each area's chunks in case of a death or server exit). Since not all equipment can be traded with blacksmith villagers, he can't use his established trade station to recover without using up diamonds which are hard to find, even in an infinite world. Also, because this is Bedrock Edition, we lack Sweeping Edge, which limits the effectiveness of mob farms for xp, and we can't use a furnace xp grinder since xp doesn't seem to save like it does in Java Edition. This means he has to mine and xp grind for well over an hour each time to recover all his equipment. He's randomly died and lost everything after the logoff/login death issue well over a dozen times.

Another very related issue, more prevalent since 1.9, and a process that was started in my family member's attempt to counteract the above issue, is an issue where he unequips all his items and stores them in a chest, then logs off, but after logging back on, all those items de-spawned from the chest. This particular version of his all equipment loss has occurred 4 times at this point, most recently just a couple hours ago at the writing of this bug report.

As the host of this home server, I have never had to deal with this item disappearance issue while logging off and on, so it seems to only be an invited member issue. I'm not certain if the following is involved in this problem, but I frequently find myself getting the "Oops! You were disconnected from Xbox Live. To invite more players, reopen your world." This is strange, because as I noted above, I have a very power and stable fiber optic connection, and I have no problem running multiple online games and steaming YouTube while playing. Still, even if I'm only running Minecraft, I can still frequently lose connection to Xbox Live. Yet, even if I am disconnected, my family member, if online at the time of the disconnect, can still play on the server and still interact with it and me, and we can both look at Xbox Live Achievements, which is only possible if connected to Xbox Live. Also, I've noticed this odd Xbox Live disconnect issue since Update Aquatic, as I launched this home server world right around the time Update Aquatic was released for Bedrock on the Windows 10 Edition, but the item disappearance problems did not affect my invited family member until 1.8.

As another side note, because of lag, massive file size, and the frequent death item loss problems that I noted first, I ended up using a Bedrock supported edition of MCEdit to trim away a lot of the unused excess (much of this excess caused by a different bug, where I stepped through a portal into the Nether, and instead of going through the proper coordinates in the Nether, I ended up in the same number coordinates of the Overworld in the Nether. Specifically, I stepped through at around x: 6000, z: -2800 in the Overworld near my main base, and ended up in the Nether, coordinates x: 6000, z: -2800, which meant my Overworld spot was now x: 48,000, z: - 22,400. It was a long trip back, but this isn't a bug report about that, plus it was a lucrative trip). This generated a brief reprieve on lag and the death item loss problem, but it came back soon after, and then 1.9 released and the problem I noted second started with items dropped in chests disappearing (the first issue did still occur with randomly logging in and dying, but without equipment, since they were all supposed to be in a chest). This is a 100% survival, vanilla server, and other than simply trimming away chunks with MCEdit, I have not used commands or mod tools to create or alter items. This world has never been converted to Creative and still have Xbox Live Achievements that can be obtained.

I tried searching for any related problems, but the closest I could find was a report on disappearing items on logging with PE 0.6 back in 2013. I think this report is different enough and fresh enough to constitute a new, non-duplicate report. Please let me know if any other info is needed. Given the suddenness and oddness of the family member's death glitch and item loss which occurs on logging in, I don't know if screenshots are even feasible.