Problem: save game at a location.  Open map again, you respawn at a higher Y level (usually the next level up, but sometimes second level above that from where you saved).  The other coordinates are close though.

This seems to be an old bug that was fixed but still occurs.  I added more info (starting from 18 August 2018) onto this resolved bug starting from 2012 but no one seems to have noticed:

_"Bed: Respawn at the wrong height?" https://bugs.mojang.com/browse/MCPE-51_

Some others have reported the problem still occuring, on that bug report.

Summary of my reports

-------------------------------

Location

My base consists of multi-level rooms dug into an extreme hill.  There are more than three levels dug out on top of each other in some areas.   

Examples:

1) There's an indoor wheat/carrot farm area stretching back as the only floor in that area, (except some mines below) with an XP farm built above it with a drop chute of 21 blocks dropping into the farm area for XP 'collection'.  In 1.5.2

• Where I saved the game (xp farm sweet spot): 286, 66, -2. 
• Where I spawned inside XP farm!: 286, 88, 4
  (could be a few blocks off - I was distracted fighting spiders in the dark!)

2) It happened again in Bedrock 1.6 when I saved in the same xp farm sweet spot (as above). 
I saved the game with my player located at 286, 66, -2.
I spawned this time, (not inside my XP Farm phew, but ontop of it), at around 286, 92, -2.

3) Once, I saved located in my bedroom (middle floor of three floors) and spawned in the brewery room a floor above that.

4) Another time I was in my top floor brewery and spawned on level above that, on top of the cliff.

5)  It happened again, this time in Bedrock 1.6.1.  I saved and exited the same survival world as described above (multi-level base dug into a large extreme hill). 
This time, I saved in the top of base Nether tower and spawned on top of it.

Saved player location: 297, 98, -4,
Spawned player location: 297, 104, -4,

To help solve this bug:

• I could attempt to capture video proof of this bug, and link on here to Youtube,

• Or submit my survival world (55Gb) for testing (my base is located just across stream from the world spawn point).  You can get a look at my base in this introduction to my survival world video: https://www.youtube.com/watch?v=xUgn1y0L-sk