Glans Wound While Using CB-6000

I recently started using this device (the CB-6000). By the second day, I felt some uncomfortable pain and noticed a small but stinging cut on my glans. Has anyone else dealt with this? If so, how did you fix it…? The location of the wound clearly points to the cage’s end opening as the culprit, likely due to repeated cycles of erection and detumescence.

Thanks for any advice.