Planning calculation per week

Hello,

I would like to plan activities up to 5% of the total availability of my resources
But I would also like these activities to be done in half a day to avoid going too much from one subject to another.
So I assigned the collaborators to 5% on this project and indicate a minimum task threshold of 0.5 days.
While scheduling I have an error message telling me that the 0.5d cannot be scheduled because it exceeds the maximum capacity.

What I understand is that the planning is done per week: 5% of 5 days of W = 2 hours. Which is below the threshold of 0.5 days.
But yet I am not specifying that the 5% is in cycles of one week. we could therefore have imagined having a 0.5 day week, then nothing the following week, in order not to exceed the load over 1 month and not 1 week.

Also would there be an option to evaluate the assignment on the project by month and not by week?

many Thanks