Do you get any errors in console while the game world loads? Can you share the full code on some github? I'll try to boot it up as well, don't see any particular thing out of the ordinary. The first thing i'd do is set some display property for first / third person on your imbuedstick.json, see if that changes anything. For you it should look like:
{
"parent": "item/generated",
"textures": {
"layer0": "mirenergy:items/imbuedstick"
},
"display": {
"thirdperson": {
"rotation": [-90,0,0],
"translation": [0,1,-3],
"scale": [0.55,0.55,0.55]
},
"firstperson": {
"rotation": [0,-135,25],
"translation": [0,4,2],
"scale": [1.7,1.7,1.7]
}
}
}