Working at a very laid-back company

Context:

I work at an IT-department of a non-profit healtcare company. I've been working here for 5 months.

I get paid above average for my age.

Typical working days are from 8am until 4:30pm.

At 10am the whole IT-department has their paid coffee break which varies from 15-30 minutes.

At noon, its lunch time, this is the 'normal' unpaid break. Some people go for a walk, some people have lunch at the company restaurant. Everyone is gone for at least 45-60 minutes.

At 3pm, we have another paid coffee break, also varying from 15 to 30 minutes.

I've had days where the whole IT-department had been absent for 2 hours. 1.5 hours of which are on company time.

My managers don't care, they join us for 99% of that time.

For the rest, I'm not busy at all. If I'm productive, I do about 1 hour of work every day.

The rest of the day, I'm doing some IT-trainings, doomscroll, doing my language courses, read documentation and walk around the office.

Sometimes I feel guilty about all this, I basically get paid to do (almost) nothing.

Days can be quite long and boring when I don't have much to do.

I've talked to my manager about my lack of tasks, he told me I'd get more work. It's been a few months and nothing happened.

Overall I'm very surprised about the work ethic, having such long breaks and lack of work don't seem normal.

What should I do? Should I enjoy my time at this laid-back company or should I try and find something more challenging?

And are there more people who have experience at this kind of company?