Welcome to the site !!
It is possible that the actuator lever has somehow lifted slightly and the push rod has slid under it which means it would not be moving when the actuator does , it would then not be able to push the lifter rod far enough to disengage the clutch plates , so what i would do is move the actuator (with the clutch cover off so you can see what its doing) , and see if it pushes the plunger out any , , if it does not , remove the clamp that holds down the actuator where the cable connects , then lift the actuator a bit , then try to pull the rod out a bit and then push the actuator down as far as it will go , then push the rod back in and turn the actuator again , and see if the rod moves now , if so then put the clamp back on and make sure it is holding the actuator down all the way and there is no upwards movement if there is a gap/slop , then bend the clamp down so it holds the actuator tight down (so it has pressure on it), hopefully that solves your issue ....