Why am I sneaking normally in Minecraft?

I installed Labymod with forge and mods like Old animation mod, reachdisplay-combodisplaymod and timechange mod. Now I have the problem because normally if you let go of the sneak button is normal, but it does not work for me I have to press the sneak button again so I stand back normal (It is not due to the keyboard because it works normally with the Badlion client ). Which, however, is very unfavorable for cw / bw and in general. I would be happy about ideas for a solution. LG and thank you in advance

If I remember correctly, you can set that in Labymod.
Look again.