How to make Alfred switch to currently open Chrome instead of opening a new window

This used to be the normal behavior for me:

1. I have a Chrome window A open
2. The focus is in another program window B
3. I bring up Alfred and type Chrome
4. Chrome is the first result, selected by default
5. I hit Enter and…
6. The focus goes to the already-opened Chrome window A

That's the same as doing Command-Tab if there are only two windows open, each of a different applications. This is how I'd like it to behave.

Now I don't know what I did wrong to make this change (or if it was me at all), but this is what happens now:

1. I have a Chrome window A open
2. The focus is in another program window B
3. I bring up Alfred and type Chrome
4. Chrome is the first result, selected by default
5. I hit Enter (nothing different so far) and…
6. A new Chrome window C gets opened behind program window B
7. Focus remains on program window B

This doesn't happen with Firefox, for example, where the expected behavior continues working.