bottom row of pixels of config background gets removed after reseting any value 1.8.9 only

[justaguywhowantsminecraftmods]

before:

after:

[moehreag]

I don't seem to be able to reproduce this (on dev)

[justaguywhowantsminecraftmods]

I was able to reproduce on two different computers. Ill try to mess around with it more later.