Margin and Padding settings of Container box in developer portal cannot be saved

We have 2 resource groups to host API Management with the same settings. In one account, the margin and padding settings of section container box can be changed and saved. In another account, the margin and padding settings of section container box CANNOT be changed and saved. They are all using the default values. We have tried many times in last week with different users with different permissions, but there was no luck. It seems something broken in that resource group.

Start by reproducing the save failure in both API Management resource groups, using the same container margin and padding settings and comparing their behavior. Investigate why the settings persist in one account but not the other; done means the container settings can be changed and saved consistently.

Written by the indexing model from the issue text.