Reducing the contact stiffness may help too, especially if this method yields significantly (by orders of magnitude) lower value than the default: Snap-fit contact snagging problem - #17 by JuanP74 - Analysis issues - CalculiX (official versions are on www.calculix.de, the official GitHub repository is at https://github.com/Dhondtguido/CalculiX).
And it’s sometimes beneficial to remove friction (although it cuts both ways since friction may help avoid rigid body motions, but only once contact is properly established).