Here’s a closer glance at the gaps.
I’ve just dealt with the annoyances for the past three years, fixing the curtain on a daily basis and stopping some of the flapping with double-stick tape. Not an elegant solution, but it worked.
Finally I took a few minutes – seriously, it took less than 10 minutes! – to fix things the right way. I folded the curtain tabs down and sewed each in place to make a rod pocket.
That solved the gap problem. I also put the outside edge tab on the outside of the rod brackets. This prevents the curtain from sliding in and allowing peekage into our house.
Then to hold everything in place, I sewed small loops to the backside of the curtain, which I hooked onto Command removable hooks. This keeps the curtain from flapping when the door opens, or when furballs want to sit in the window to monitor the front door.