Insert Still does not use Standard Still Duration?

This used to work as I expected, but with 18.6.6, I have set Standard Still Duration to 1.25 sec, but in both the Cut and Edit pages, an "Insert" of a still to the Timeline results in a 2.29 Sec clip. I have tried changing the Standard Still Duration to something else (e.g. 1.5 Sec) but still get the same result.
Am I missing something?

[Peter Chamberlain]

Are you setting this is preferences, user, editing, general settings, standard still duration?

What is the timeline frame rate?

Yes: preferences, user, editing, general settings, standard still duration

Timeline frame rate: 50 fps