Why does moving some apps to sd result in even more internal memory usage in Android 6 marshmallow?

[AC Question]

Since upgrading to marshmallow, I've noticed moving apps to sd behaving very oddly.
Previous Android behaviour in this regard makes explaining the problem confusing so I'll just use a example to demonstrate what I mean.
Take Flixster. On internal memory, it uses 10.3 Mb. If I move it to sd, it uses 21.66 Mb of internal as well as 12.25 Mb of sd?!?
How does that remotely make any sense?

 

[AlphaTango414]

Have you tried rebooting the device after you have moved the app to the SD card?

 

[Rukbat]

Each piece of the app is moved to the SD card separately. A link is left in internal storage pointing to where that piece is on the SD card. If the pieces are small enough, and there are enough of them, the links take more space than the code you moved to the SD card. (You can't run an app from the SD card itself, unless you root the phone then flip the mounting so the SD card becomes "internal storage" - External 2 Internal SD (Root). It's not recommended, though - apps keep writing to the location they're installed to - the SD card, in this case. SD cards aren't designed for constant writing, the way eMMC (the internal storage in the phone) is. It'll kill the card pretty quickly.

 

[lucid_enigma]

I understand that some remains on the SD card when moving, but this is doubling the amount of internal memory used by moving to SD as well as the space then used on SD?!?
That makes no sense?!?
Before the Marshmallow update this never occurred. Now it happens with many apps (though not all).
And I've tried restarting but that changes nothing.
I'd love to not use SD for apps but with HTC software and growing OS, I really don't have much choice. 16GB is becoming barely enough to hold the system and basic list of apps!

Edit: I am currently moving apps to internal memory to save internal memory space?!?