Just tried my old Note4 stylus and it made no difference, still not working.
But what I did notice is that:
In game play/battles if you tap on two adjacent cells/troops with the S-pen they switch positions. The result is the same as swiping.
This is annoying as hell as it takes a bit of getting use to. However, once mastered you will not notice the difference. This is not a fix but can allow some game play with the S-pen.
All this cause something got messed up. What happened to QA SG?