In my survival world (windows 10) I created a 4 wide by 5 tall nether portal. I use droppers in the top corners to turn it on and off - a flint and steel in one to turn on and lava in the other to turn off. There is a normal game-generated portal in the nether. Going to the nether is no problem.

The Problem: Coming back through to the overworld the player (me) is spawned at the top of the portal - my head is briefly in the obsidian block (i think) - and i then drop to the floor taking a small amount of fall damage.

Where I get spawned in the portal seems to relate to which part is initially lit. If I manually ignite a bottom obsidian block, when I come back from the nether - I am spawned at the bottom of the portal, standing on the obsidian. What I think should happen is that the player is spawned at the bottom of the portal no matter where it was initially lit. If the portal were really large and lit at the top - a player could almost die coming back through it.

Thank you for your time