I have this DataManagerClass.kt in my app that causes crashes only in release build. The crash states something like this:

import com.viva.yag.source.remote.retrofit.ApiService
import com.viva.yag.model.AuthModel
import com.viva.yag.model.CarModel
import com.viva.yag.model.MainResponseModel
import com.viva.yag.model.ReservationModel
import com.viva.yag.source.remote.retrofit.ApiResponse
import io.reactivex.Observable
import io.reactivex.android.schedulers.AndroidSchedulers
import io.reactivex.schedulers.Schedulers
import okhttp3.RequestBody
import retrofit2.Response

class DataManagerClass: ApiResponse {
override fun requestForSignUp(signUpModel: AuthModel): Observable<Response<MainResponseModel>> {
    return ApiService.get().requestForSignUp(signUpModel)
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
}

override fun requestForSignIn(signInModel: AuthModel): Observable<Response<MainResponseModel>> {
    return ApiService.get().requestForSignIn(signInModel)
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
}
//so on other identical methods for API requests
}