Fix as per @jflyper's comments

src/main/drivers/bus_i2c.h

@@ -45,8 +45,9 @@ typedef enum I2CDevice {
 #define I2CDEV_COUNT 4
 #endif
 
-// Macro to convert CLI bus number to I2CDevice.
+// Macros to convert between CLI bus number and I2CDevice.
 #define I2C_CFG_TO_DEV(x)   ((x) - 1)
+#define I2C_DEV_TO_CFG(x)   ((x) + 1)
 
 // I2C device address range in 8-bit address mode
 #define I2C_ADDR8_MIN       8

src/main/io/dashboard.c

@@ -75,7 +75,7 @@
 PG_REGISTER_WITH_RESET_TEMPLATE(dashboardConfig_t, dashboardConfig, PG_DASHBOARD_CONFIG, 0);
 
 PG_RESET_TEMPLATE(dashboardConfig_t, dashboardConfig,
-    .device = DASHBOARD_I2C_INSTANCE,
+    .device = I2C_DEV_TO_CFG(DASHBOARD_I2C_INSTANCE),
     .address = DASHBOARD_I2C_ADDRESS,
 );