Looking good in here age! So yeah technically the boards are made up of hundreds of smaller cob dioded. A single source cob is just that 1 big chip on a heat sink. The boards allow for more even distribution and transfer of heat which makes them a bit more efficient.
A little weirding from change of lights: led to cob. T5 to led or cob. Or any of those is normal.... the sun is something else and that's not even mentioning other environmental factors. But remember this, it's a weed, itll survive just fine! Grow on my friend