Slow down music with minimal pitch distortion

Audacity 3.1.3
MacOS 10.15.7

I’m trying to slow down some lyrics with minimal pitch distortion.
I used Effect > Sliding Stretch > Initial Tempo Change -50%
I think it worked OK

However, I seem to have lost the ability to loop bits of the music.
The loop on/off button is on but the music doe not loop nor do those black triangles appear in the timeline.

Shouldn’t I still be able to loop after this effect?