Generally I think you are doing pretty well, based on the time between the need to hone. I think you need to work on a few small things. The root cause might be that you are getting a little complacent. The strop needs some serious treatment, like hand oil, for several days. That scratching sound is too aggressive. I put all kinds of oils into my strop to keep it supple. I won't go into detail as I'm always experimenting instead of staying on course. The strop needs to come down a little. The stroke needs to slow down. You need more strop tension too. The edge will begin to get rolled from a perpendicular stroke. The edge should be angled when stropping (or an x pattern can help guard against rounding).

There are two ways to strop an edge. 1) rounding the edge slightly and 2) smoothing it, but maintaining the geometry. You've started rounding a little more than you used to. It isn't wrong, it's just different. What you should do is simply hone it (or get it honed) and follow the advice above and throughout the thread to try to extend maintaining your edge longer. A simple touch up honing is a very easy thing to accomplish and it's probably about time you dove in.