I cannot pull a shot or achieve a smooth flow under normal force.
Note the NEO's Flow Control Portafilter requires a grind size much coarser than typical espresso brewing calls for, as its inner "Flow Control" properties are already working to slow the passage of water through the portafilter to build pressure within the brew head.
Because of this, use of too fine of a grind size will either compound these properties too much and restrict your flow, or the small particles will make their way beyond cleanable reach and cause a semi/permanent build-up or clog.
If you are unable to pull a shot or achieve a smooth flow under normal force (30 lbs applied to the NEO lever), carefully terminate your attempt by slowly releasing the lever.
Next, determine which Flow Control Portafilter version you have (version 1: non-removable spout or version 2: removable, screw-in spout) and follow troubleshooting next steps accordingly.