Stuck at creating a basic Vendor Model in BT-Mesh

Question

Hi,
I have followed the Chat Sample Walkthough, Vendor Model Development Overview and other examples from different vendors using zephyr, but I'm getting stuck at the following point:

In the model_handler at bt_mesh_elem list I add my vendor model with callbacks:

static struct bt_mesh_elem elements[] = {
	BT_MESH_ELEM(
		1,
		BT_MESH_MODEL_LIST(
			BT_MESH_MODEL_CFG_SRV,
			BT_MESH_MODEL_HEALTH_SRV(&health_srv, &health_pub)),
		BT_MESH_MODEL_LIST(
			BT_MESH_MODEL_VND_CB(BT_MESH_VIBE_SERVER_VENDOR_COMPANY_ID,       \
				BT_MESH_VIBE_SERVER_VENDOR_MODEL_ID,                      \
				vibe_server_opcode_list, \
				NULL,                   \
				NULL, \
				&vibe_server_cb)
		)),
};

I have added init, start and reset functions in my vendor model with log outputs, but those never get called. I trimmed down the chat sample a lot and had to create the server vendor model (since the chat model doesn't really show a server approach), but I think I may have done something incorrectly or missed a step.

custom vendor model header:

#ifndef VIBE_SERVER_H
#define VIBE_SERVER_H

#include <zephyr/bluetooth/mesh.h>

// Company ID is Nordic
#define BT_MESH_VIBE_SERVER_VENDOR_COMPANY_ID 0x0059
#define BT_MESH_VIBE_SERVER_VENDOR_MODEL_ID 0x0020

// OPCodes for the Vibe Server
#define BT_MESH_VIBE_SERVER_OP_STOP BT_MESH_MODEL_OP_3(0x20, BT_MESH_VIBE_SERVER_VENDOR_COMPANY_ID)

// Vibe Server Model
extern struct bt_mesh_model vibe_server;

// Handlers
void handler_vibe_sever_stop(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *ctx, struct net_buf_simple *buf);

// Callbacks
void vibe_server_init(struct bt_mesh_model *model);
void vibe_server_start(struct bt_mesh_model *model);
void vibe_server_reset(struct bt_mesh_model *model);

// OPCode List for the Model
static struct bt_mesh_model_op vibe_server_opcode_list[];

// Callback Struct
static struct bt_mesh_model_cb vibe_server_cb;

#endif /*VIBE_SERVER_H*/

custom vendor model source:

#include <zephyr/bluetooth/mesh.h>
#include "vibe_server.h"
#include "mesh/net.h"
#include <string.h>

#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(vibe_server, 3);

/* ============================
*  Vibe Server Handler Functions
*/ 
void handler_vibe_server_stop(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *ctx, struct net_buf_simple *buf){
    printk("vibe_stop");
};

/* ============================
 * Vibe Server Callbacks
*/
// Init Callback. It is called when the model is initialized.
void vibe_server_init(struct bt_mesh_model *model){
    LOG_INF("Vibe Server Init!\n");
};

// Start Callback
void vibe_server_start(struct bt_mesh_model *model){
    LOG_INF("Vibe Server Start!\n");
};

// Reset Callback.
void vibe_server_reset(struct bt_mesh_model *model){
    LOG_INF("Vibe Server Reset!\n");
};

/* ============================
 * Vibe Server Model
*/
struct bt_mesh_model vibe_server = {
    .id = BT_MESH_VIBE_SERVER_VENDOR_MODEL_ID,
    .op = vibe_server_opcode_list,
    .cb = &vibe_server_cb,
};

/* ============================
 * Vibe Server Model Entries
*/
// OPCodes Struct.
static struct bt_mesh_model_op vibe_server_opcode_list[] = {
    {BT_MESH_VIBE_SERVER_OP_STOP,
    BT_MESH_LEN_MIN(0),
    handler_vibe_server_stop},
    BT_MESH_MODEL_OP_END
};

// Callback Functions Struct
static struct bt_mesh_model_cb vibe_server_cb = {
	.init = vibe_server_init,
	.start = vibe_server_start,
	.reset = vibe_server_reset,
};

model_handler:

#include <stdio.h>

#include <zephyr/bluetooth/bluetooth.h>
#include <bluetooth/mesh/models.h>

#include "model_handler.h"
#include "vibe_server.h"

#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(model_handler, 3);

/******************************************************************************/
/*************************** Health server setup ******************************/
/******************************************************************************/
/* Set up a repeating delayed work to blink the DK's LEDs when attention is
 * requested.
 */
static struct k_work_delayable attention_blink_work;
static bool attention;

static void attention_blink(struct k_work *work)
{
	//static int idx;
	//const uint8_t pattern[] = {
	//	BIT(0) | BIT(1),
	//	BIT(1) | BIT(2),
	//	BIT(2) | BIT(3),
	//	BIT(3) | BIT(0),
	//};

	//if (attention) {
	//	dk_set_leds(pattern[idx++ % ARRAY_SIZE(pattern)]);
	//	k_work_reschedule(&attention_blink_work, K_MSEC(30));
	//} else {
	//	dk_set_leds(DK_NO_LEDS_MSK);
	//}
}

static void attention_on(struct bt_mesh_model *mod)
{
	attention = true;
	k_work_reschedule(&attention_blink_work, K_NO_WAIT);
}

static void attention_off(struct bt_mesh_model *mod)
{
	/* Will stop rescheduling blink timer */
	attention = false;
}

static const struct bt_mesh_health_srv_cb health_srv_cb = {
	.attn_on = attention_on,
	.attn_off = attention_off,
};

static struct bt_mesh_health_srv health_srv = {
	.cb = &health_srv_cb,
};

BT_MESH_HEALTH_PUB_DEFINE(health_pub, 0);

/******************************************************************************/
/******************************** Vibe Server *********************************/
/******************************************************************************/
static struct bt_mesh_elem elements[] = {
	BT_MESH_ELEM(
		1,
		BT_MESH_MODEL_LIST(
			BT_MESH_MODEL_CFG_SRV,
			BT_MESH_MODEL_HEALTH_SRV(&health_srv, &health_pub)),
		BT_MESH_MODEL_LIST(
			BT_MESH_MODEL_VND_CB(BT_MESH_VIBE_SERVER_VENDOR_COMPANY_ID,       \
				BT_MESH_VIBE_SERVER_VENDOR_MODEL_ID,                      \
				vibe_server_opcode_list, \
				NULL,                   \
				NULL, \
				&vibe_server_cb)
		)),
};

static const struct bt_mesh_comp comp = {
	.cid = CONFIG_BT_COMPANY_ID,
	.elem = elements,
	.elem_count = ARRAY_SIZE(elements),
};

/******************************************************************************/
/******************************** Public API **********************************/
/******************************************************************************/
const struct bt_mesh_comp *model_handler_init(void)
{
	k_work_init_delayable(&attention_blink_work, attention_blink);

	return &comp;
}

Is my approach to the custom vendor model doable or should I follow more strictly the chat sample with it's chat_cli struct and function pointers?