I just took delivery of the Flex about 2 weeks ago. Everything looks and works well except the S Pen gives me quite a bit of trouble. About a week after I have start using my new laptop, there is an error message popping up as a message notification to the right side of the screen. It said "Connection error: Connection failed. Check the connection environment or the battery level of the S Pen". I have tried to reset the S Pen through the Samsung settings panel to no avail. I have called the tech support line and I believe he has re-installed the driver on my machine and it seems to work, but only for a few days because it came right back to where it was before. I called again and the tech guy won't able to help much. He did offer to send me a new S Pen and I'll see if that may cure the problem.
Mine is doing the samething it just started today. I have unpaired it and repaired it but I'm still getting the same message. I would like know how to fix it. I love the flex I have the 15" version.
I have a similar issue, the support staff just checked to see if my drivers/windows/samsung update were all up to date and they were. I bought a new spen because i didnt want to wait for warranty to fulfill and this did not fix the issue.