Since upgrading to iOS 13 my notifications are not poping up on my AW4. I've since upgraded to iOS 13.1, same results. ☹️ I rebooted both iPhone 11 & AW4, verified all settings, still no luck.
I've been having issues with notifications not appearing on my watch for most of the summer. My phone was on 12.4 and watch was on 5.x. I haven't noticed if it has fixed itself since upgrading both to current releases.