After clicking on bar chart percentage changes

[Applicable88]

Hello,

Sometimes I'm setting up a bar chart with very easy function like this for example:

sum(aggr(count(Specific value),Ordernumbers))

/

sum(aggr(Count(all value),Ordernumbers))

After setting up a time dimension I get the following:

As you can see I get a several 100% bars. When I click on them the percentage value changes to what is actually right:

For Example calendarweek 2020/25 :

Why it returned the value of 100% in the first place ?

Indeed a specific value devided to all values at that caladar week would be 28,6% and not 100%.

Why it displayed 100% in the first place and how to fix that? And it might only happens with Aggregations-functions?

Hope someone can help me with this understanding. 

Best.