Is there a sight screw that you have screwed into the receiver that is sticking into the receiver tube?
You may have to pull the trigger back in order to get the bolt back into the receiver, most bolt 22's are made that way.
Make sure all the pins in the bolt are all the way in and double check that the extractors are put in the bolt correctly.
If nothing else works, strip one part off of the bolt at a time and try every time a piece is taken off, be sure to pull back on the trigger every time. Look carefully to se if you can tell where the problem is. The pulling of the trigger should pull the part in the bottom of the receiver tube. If it does not go down when the trigger is pulled, look into what is keeping that part from not going down.
It is a process of illimination sometimes.
Let us know if either helps.
My Best, John K