Transferring firms halfway through ACA training contract?

Has anyone ever left their ACA contract before the 3 year period? Is it frowned upon?

I am just over 2 months into my current firm but I am not liking the vibe of this office. There is very little work and I feel like I have no proper support. Also living costs are pretty high and I feel quite lonely.

Anyway, so I went to assessment centre for another firm. Although I haven't heard back from them yet, I was just wondering is it going to affect my reputation. Will I be labelled as a betrayer? I am so worried what I am going to say because currently I am the only junior in my existing office. And if I leave, they will have no junior basically. Tbh, they haven't even scheduled me much client work anyway.... but thats a story for another day.

If there is anyone who has ceased their contract early and transferred to another audit firm, please share your experience.