You're absolutely right Entry #19 [M-F] pointed to STAR 2503, which had "NONE" under the Auto Attendant, but listed the Timeout to transfer to Hunt Group 400.
I tried pointing 19 to Hunt Group 400, but it popped up a dialogue box asking me to select an extension. (And wouldn't let me add one there.)
Instead I left 19 pointed at 2503, but updated the Auto Attendant under 2503 from "None" to the HG 400. (?)
Sorry to be so dense (and thanks for taking pity, lol). I inherited this system and have figured out a fair piece - but get mired in this foundational stuff. (We had a Mitel shop that set it all up eight years back, but they closed a few years ago and I wasn't given a budget to hire someone else, since I "know the phone system" ... lol.)