Uncaught Kotlin exception: kotlin.native.IncorrectDereferenceException:

Question

I'm still relatively new to KMM and a project I'm working on keeps yeilding this error:

Uncaught Kotlin exception: kotlin.native.IncorrectDereferenceException: illegal attempt to access non-shared dev.mrbe.haarShared.HaarSDK@abc468 from other thread
    at 0   kotlinmultiplatformsharedmodule     0x00000001020909a1 kfun:kotlin.Throwable#<init>(kotlin.String?){} + 97 (/opt/buildAgent/work/c5a36d4d82b914cf/kotlin/kotlin-native/runtime/src/main/kotlin/kotlin/Throwable.kt:24:56)
    at 1   kotlinmultiplatformsharedmodule     0x0000000102089dad kfun:kotlin.Exception#<init>(kotlin.String?){} + 93 (/opt/buildAgent/work/c5a36d4d82b914cf/kotlin/kotlin-native/runtime/src/main/kotlin/kotlin/Exceptions.kt:23:58)
    at 2   kotlinmultiplatformsharedmodule     0x0000000102089fcd kfun:kotlin.RuntimeException#<init>(kotlin.String?){} + 93 (/opt/buildAgent/work/c5a36d4d82b914cf/kotlin/kotlin-native/runtime/src/main/kotlin/kotlin/Exceptions.kt:34:58)
    at 3   kotlinmultiplatformsharedmodule     0x00000001020c140d kfun:kotlin.native.IncorrectDereferenceException#<init>(kotlin.String){} + 93 (/opt/buildAgent/work/c5a36d4d82b914cf/kotlin/kotlin-native/runtime/src/main/kotlin/kotlin/native/Runtime.kt:31:50)
    at 4   kotlinmultiplatformsharedmodule     0x00000001020c508f ThrowIllegalObjectSharingException + 623 (/opt/buildAgent/work/c5a36d4d82b914cf/kotlin/kotlin-native/runtime/src/main/kotlin/kotlin/native/concurrent/Internal.kt:115:11)
    at 5   kotlinmultiplatformsharedmodule     0x00000001022a1b52 _ZN12_GLOBAL__N_128throwIllegalSharingExceptionEP9ObjHeader + 34
    at 6   kotlinmultiplatformsharedmodule     0x00000001022a389d _ZN12_GLOBAL__N_136terminateWithIllegalSharingExceptionEP9ObjHeader + 13
    at 7   kotlinmultiplatformsharedmodule     0x00000001022a39b5 _ZNK27BackRefFromAssociatedObject3refIL11ErrorPolicy3EEEP9ObjHeaderv + 133
    at 8   kotlinmultiplatformsharedmodule     0x0000000102070e25 -[KotlinBase toKotlin:] + 21
    at 9   kotlinmultiplatformsharedmodule     0x0000000102295058 Kotlin_ObjCExport_refFromObjC + 88
    at 10  kotlinmultiplatformsharedmodule     0x0000000102040676 objc2kotlin.505 + 230
    at 11  haar                                0x00000001006b3181 $s4haar11MyViewModelC10addBooking7bookingySo031KotlinmultiplatformsharedmoduleF0C_tYaFTY0_ + 273 (/Users/essienedim/Desktop/HAAR /haar/haar/ContentView.swift:422:33)
    at 12  libswift_Concurrency.dylib          0x00007ff833c40426 _ZN5swift34runJobInEstablishedExecutorContextEPNS_3JobE + 310
    at 13  libswift_Concurrency.dylib          0x00007ff833c411bd _ZL17swift_job_runImplPN5swift3JobENS_11ExecutorRefE + 77
    at 14  libdispatch.dylib                   0x00000001014dfe77 _dispatch_continuation_pop + 87
    at 15  libdispatch.dylib                   0x00000001014def27 _dispatch_async_redirect_invoke + 997
    at 16  libdispatch.dylib                   0x00000001014f1e77 _dispatch_root_queue_drain + 414
    at 17  libdispatch.dylib                   0x00000001014f2b17 _dispatch_worker_thread2 + 278
    at 18  libsystem_pthread.dylib             0x00007ff833e39f8a _pthread_wqthread + 256
    at 19  libsystem_pthread.dylib             0x00007ff833e38f57 start_wqthread + 15
CoreSimulator 857.7 - Device: iPhone 14 Pro (C24AA3AD-B79D-437E-BCB7-A15C83C0F412) - Runtime: iOS 16.0 (20A360) - DeviceType: iPhone 14 Pro
(lldb) 

I have seen this and some other posts on this but when I try using the freeze() method, I keep getting an Unresolved reference: freeze. I can't seem to figure out what exactly I'm doing wrong and honestly, what I should be freezing exactly.

Here's the function that seems to be triggering this Exception:

func addBooking(booking: Booking) async {
        await  sdk.postBooking(booking: booking)
    }

The SDK class is initialise in the view model like so:

class MyViewModel: ObservableObject {
let sdk: HaarSDK

...

init(sdk: HaarSDK) {
    self.sdk = sdk
    ...
          
  }
}

Main View:

struct MainView: View {
    
    @StateObject private var viewModel: MyViewModel
    
    init() {
        
        let sdk =   HaarSDK(databaseDriverFactory: DatabaseDriverFactory())
        
       let viewModel = MyViewModel(sdk: sdk)
       _viewModel = StateObject(wrappedValue: viewModel)
     }

...
    }

SDK class (Kotlin):

class HaarSDK(databaseDriverFactory: DatabaseDriverFactory) {
    private val database = Database(databaseDriverFactory)
    private val api = HaarApi()

    ...

    @Throws(Exception::class)
    suspend fun postBooking(booking: Booking) {
        api.sendBooking(booking)
    }
  ...
}

Database:

internal class Database(databaseDriverFactory: DatabaseDriverFactory) {
    private val database by lazy {
        AppDatabase(databaseDriverFactory.createDriver())
    }
    private val dbQuery = database.appDatabaseQueries
...
}

API class:

class HaarApi {
    private val httpClient = HttpClient {
        install(JsonFeature) {
            val json = Json { ignoreUnknownKeys = true }
            serializer = KotlinxSerializer(json)
        }
...

  suspend fun sendBooking(booking: Booking) {
        val response: HttpResponse = httpClient.post(BOOKING_ENDPOINT) {
            contentType(ContentType.Application.Json)
            body = booking
        }
...
}