2013 Mustang GT Engine Knocking Noise on Coldstart

When I start my 2013 GT in the morning, I sometimes hear a loud clunk, knocking, popping type sound from the engine. It happens completely random mostly when it’s below 20 degrees Celsius outside. It only happens in the morning. The RPM’s go up and down while it is doing this. It sounds like the engine is going to die, then sounds normal, then clunks again, then after 20 seconds, it idles out and sounds perfect. No issues while the car is warm at all. Runs better than ever. Any ideas?