After removing the freshness seal, please allow the pod to absorb the liquid for 1-3 minutes before use. This will prevent damage to the cotton within the coil, which results in a burnt taste. 
Also, check the e-liquid level of the pod. When the e-liquid is exhausted you will get a burnt taste, which means it’s time for a new pod.
If the burnt taste is light and there is still e-liquid in the pod, stop vaping for 1-3 minutes to allow more e-liquid to absorb into the coil and try vaping again. Excessive chain vaping can cause the coil to dry out; pausing to allow the coil to re-saturate with eliquid will solve this.