In VLIDE it behaves normally.
I can't find any errors by using VLIDE.
And that is why I don't mention of using it.
From the command prompt, the 1st set of "initget" looks fine:
(initget "A B C")
(setq ABC (getkword "\nSelect A/B/C: "))
Select A/B/C: -> A
"A"
but the 2nd set has a problem:
(initget "D E F")
(setq DEF (getkword "\nSelect D/E/F: "))
Select D/E/F: -> D
Invalid option keyword.