Remap ctrl AND use ctrl-tab to switch apps: double tab needed

I’m using gnome-tweak to remap ctrl (switching ctrl and alt). I then use the system settings to map ctrl-tab to app swtching.

When I did this first, it worked. As expected

But since upgrade and reboot, this now requires a double tab press before the switcher comes up. I.e. on the first ctrl-tab the tab seems to go into the application, and only when I got tab again, the app switcher comes up.

The two changes work fine independently, but when I combine them, the strange behaviour occurs.

Any ideas? Any other ways of switching keys outside of gnome-tweak?