Is the number of counterbalancing groups in shelf limited?

Version 2022.2.4

At the moment I am trying to create a counterbalanced online experiment with shelf.
I have 5 groups to counterbalance. The problem is that I can only define 4 groups in the shelf component.
This means that if I define for example groups: “A”, “B”, “C”, “D”, “E” and groupSizes: 1,1,1,1,1 and I click on the update button, then the first line in group “A” and groupsize “1” is deleted.

Does this mean that I can only counterbalance four groups?

Thank you very much!

I don’t know why but it worked when I wrote the groups and groupSizes from left to right (not from top to down):