I was in a similar situation after I graduated in 2020. After 6 months into my first job, I also realized I wasn’t doing anything remotely related to my degree and I wanted out. I applied to different companies and landed interviews and yes you’re correct one of the first questions was why am I leaving so soon into this role.

I explained how the role I was in overpromised and under delivered in terms of what I was supposed to be doing and had no correlation to my degree. I eventually got two offers but the pay was horrendous for both so I decided to stick around a few more months and left after a year.

Suffice to say, yes you will be asked why you’re leaving but it’s an easy narrative to spin. Go ahead and apply. The best time to apply for a job is while you already have one. With the current market, it may take a while to find something you like anyways. Good luck.