I can do repeated attacks with seemingly unlimited maps, but the battle never seems to have actually happened. No damage is registered, no resistance deducted, no loot added to my bank, and no forces lost. I've only done GAs so I don't know if it's just that or other types of attacks as well.
war timeline: https://politicsandwar.com/nation/war/timeline/war=525399
Update: I got it to work but only after many attempts, and only after clicking to another page. Clicking "back to wars" resets everything again.