I saw this post made by Wayne Zhang a while ago explaining the Skateboard lights.
So the blinking light relates to something abnormal happening with either EMO or the Skateboard. As you’ve done things such as changing USB-C cables / unplugging the cable and re-connecting it again and then placing EMO back on the Skateboard and see if it resolves the issue.
I’ve seen this a few times as well with my EMO. What I normally do is unplug the USB-C cable from the skateboard, wait a few minutes and securely connect it back again. I also clean my EMO’s feet with sticky tape (as you also do). After doing this, that normally resolves the blinking and EMO continues to charge normally once again.
I guess if this is constantly happening for you, it would be best to contact support once again and explain the problem. It could be a faulty skateboard, it might not always be an EMO problem.