Trying to half the duration of notes without creating rests? Insert mode makes it wonky!

Trying to change quarter note triplets into eighth note triplets using insert mode makes it really screwy
I’ve watched the Dorico video but it doesn’t come out like the video shows.:
(OK I had to delete the link that I originally had pasted here to show the Dorico video that I watched. Not allowed to post links)

Dang it!! I tried to put a second screenshot of what I started with but the forum won’t let me post more than one because I’m a new user!??? Really?? I’m trying to show a before and after example but it won’t let me. How un-new do I have to be?

So the second screenshot was going to be the four bars of quarter note triplets I was trying to convert. But it’s more important the the end result be seen.

Thank you.

Select your notes. Insert mode ON.
Edit>Filter>Tuplets. (or use the right-click menu)
Press Delete.
Re-select the notes (now they are just crotchets).
Convert to quavers (press 5).
Convert to triplets (press ;).

Newer than a first-time poster, as truly inconvenient as that sometimes is.