Why do I have oil in my degas bottle?

Hello, my first question is: what engine do you have in your truck? Is it a Powerstroke Diesel 6.0L engine? Or is it a gasoline engine? If it is Diesel, this vehicle and engine has some known historical issues with the engine oil cooler and EGR cooler. Both of which can cause oil and coolant intermix if there is a breach of either of these coolers. Additionally, the cylinder head gaskets may leak due to over pressurization of the cylinders from the turbo charger due to over-boost or even base engine design flaws. There are quite a few published and unpublished technical directives about diagnosing and repairing these vehicles. An experienced 6.0L Diesel engine technician would be quite helpful. If it is not a Diesel engine, the same principles apply; oil can get into the coolant due too a breath of a cooler or cylinder head gaskets. Hands on testing is needed. https://repairpal.com/auto-repair-near-me