NonLinear ArcLength solver : Amplitude of vertical reaction is exactly the double of the applied vertical load

Perhaps I am missing something, but the observation mentioned in the title could only be explained by a incrementation of the load.
Could someone help me out with an explanation ?
.gh attached.
Thanks, Roman (60.6 KB)

Hello @roman,
thanks for your bug report! This is an error. I added an issue here and will try to solve it in the next few days.
– Clemens