This struct is losing it's values; it should be serialized (private member marked [Serializable] in MyHexagon.cs)

OffsetCoordinate.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

// NOTE: this struct is assumed to be column ordered, i.e. compatable with even-q and odd-q offset coordinate layouts
public struct OffsetCoordinate 
{
	public int col { get { return _col; } }
	public int row { get { return _row; } }
	int _col;
	int _row;

	public OffsetCoordinate(int c, int r)
	{
		_col = c;
		_row = r;
	}

	public static OffsetCoordinate operator +(OffsetCoordinate a, OffsetCoordinate b)
	{
		return new OffsetCoordinate(a.col + b.col, a.row + b.row);
	}

	public static bool operator ==(OffsetCoordinate a, OffsetCoordinate b)
	{
		return a.Equals(b);
	}

	public static bool operator !=(OffsetCoordinate a, OffsetCoordinate b)
	{
		return !a.Equals(b);
	}

	// LINK: http://stackoverflow.com/questions/2542693/overriding-equals-method-in-structs
	public override bool Equals(object obj)
	{
		if (!(obj is OffsetCoordinate))
			return false;

		OffsetCoordinate c = (OffsetCoordinate) obj;
		return col == c.col && row == c.row;
	}

	public override int GetHashCode()
	{
		return col ^ row;
	}
}