How do I frame it if I leave the firm before one year?

[autisticunemployedbitchparents]

Got told to go in July but resigned before I got pushed out.
When asked why I stayed for less than a year, ( I joined sep 2023) what do I say.
I was ex-Big 4 restructuring.

Most recent good (and in this case 100% true) reason I came across was 'they weren't giving me enough to do, the role did not not materialise/develop in the way everyone had expected it to when I was recruited'.