I create a FK/IK switch system for the arms of my rig ( I know ,it's quite basical). To controle it , I create a parameter (Integer) which controle the Blend of the IK (the value of the parameter = the value of the Blend). It works but when I create an animation of the FK/IK's controller ( a switch from FK to IK ) , the IKs are broken ( it's like if the IKS are no more applied to the bones ). The only way that I found to ‘'fix’' it was to switch the IK Dampening from 0 to 1 to 0 but it did not solve completly the problem ( it comes back after some manipulations ).

I share the files who contains the problems ( with a simple animation of the FK/IK's Switch).

Thanks in advance to anyone who takes the time to read this and maybe help me.

the FKIK switches really should be float parameters
you have keys on the translates of the Ctrl_Left_Hand_IK which are causing issues

I'd strongly recommend having a look at how the autorigs are set up - or a simpler example, on the Character Shelf there are a couple of rigged characters ‘simplemale’ and ‘simplefemale’ - these assets would be a good way to se how many of these things are usually done in Houdini.