Thanks for the reply, and sorry for the late response. I didn't use to experience the issue, but now I am and it seems to be happening a lot and very consistently. The Surface app is telling me that the battery has 80% battery life left. I have tried completely "forgetting" the pen and repairing it, but that is all that I have tried so far as I'm not sure what else to try. Thank you for your help! I will install the latest updates as well while I wait for your response.
The ONE thing I have noticed is that it seems to happen strictly after hibernates, and not sleeps. So if I force the computer to hibernate and then resume, it will not function until re-paring.