If in a minecart or boat traveling long distances, often at the point of crossing map edges, my character will respawn in a different transport a small distance from the original transport. The original transport will still contain any mob that was in it and in the case of one boat, my first horse continued rowing in the same direction as when I de/respawned.

This bug can also teleport me vast distances to previous de/respawn points, for example, when my daughter was traveling a long way from my character. She was rowing across to get back to me after dying and respawning at the source. I was about 3,000 blocks away walking in a Desert Temple. Next thing I was back in a boat at a point I'd de/respawned before and close to her character!

This appears to be a lagging/processor overloading type of glitch with the software reloading a last known location in a specific chunk(? sorry, new to the terminology) It occurs with or without my daughter connected to the W10 host with her iOS PE version. It has occurred in the last three version releases and still seems to continue. Getting a few seas festooned with boats and chests full of minecarts!

I've seen mention of a similar issue on saving and returning or of duplicating transports (pigs, boats, minecarts) but not exactly the same as above. (Sorry first bug post!)