Sounds like a sticking valve, or possibly (but imo less likely) a problem with the timing.

The other option is that the trigger itself is setup incorrectly, perhaps sears are passing but the hammer is not being released until the lever is opened. This could also suggest something in the “cocking gears” that run alongside the action isn’t set up right.

It would be helpful to know what the ‘click’ is after pulling the trigger, but then I guess if you knew that you could probably figure out the issue yourself