SQLite-net-pcl - SQLite.SQLiteException: Cannot add a PRIMARY KEY column

I seem to be hitting all sorts of problems today. I simply cannot get Sqlite-net-pcl to behave correctly when signing an APK. Debug and release work fine but everytime I create a signed version of the APK the app crashes with this issue:-

SQLite.SQLiteException: Cannot add a PRIMARY KEY column

Here is an example of my model:-

using SQLite.Net.Attributes;
using System;

namespace App.BusinessLayer.LocalObjects
{
[Preserve(AllMembers = true)]
public class LocalTip
{

    public int ID { get; set; }

    [PrimaryKey, Column("tipObjectId")]
    public string objectId { get; set; }
    public DateTime createdAt { get; set; }
    public DateTime updatedAt { get; set; }
    public string Title { get; set; }
    public string Bet { get; set; }
    public string Description { get; set; }
    public string Rating { get; set; }
    public string Time { get; set; }
    public string Bookies { get; set; }
    public string Url { get; set; }
    public int Status { get; set; }
    public Double Odds { get; set; }
    public int Outcome { get; set; }

    public LocalTip()
    {
        this.objectId = " ";
        this.Title = " ";
        this.Bet = " ";
        this.Description = " ";
        this.Rating = " ";
        this.Time = " ";
        this.Bookies = " ";
        this.Url = " ";
    }
}

}

Has anyone seen this before?