Yeah, over here the same. I get a 30 minutes lunch break during which I don't get payed. And an extra 15 minutes 'coffee break' if I work the eight hour shift. So I'm basically 8,5 hours at work but I get paid for eight.
My old job was like that as well, 8.5 hour shift. 30 minutes for lunch, 15 minute paid break.
The thing is there's no set lunch break or anything. People do whatever they want as long as they got their work done. Honestly, I only look a break on one of the days. An hour break is too long for me, I get bored and don't know what to do.
I can leave a comment on the time entering form. I'll put down 40 hours for the week but leave a note saying I'm not sure how it's handled and to correct it if necessary. It has to be approved by my boss of course. I feel like it's the best option.
edit. I also forgot, I was hired through a staffing agency. The staffing agency pays me, not the people I work for. So I'm not sure how that affects everything