The default resource is not selected in the online store with the configuration similar to described:
- resource Res1 is included in the resource category Cat1;
- resource category Cat2 is parent for the resource category Cat1;
- resource Res1 is set as default for the resource category Cat1;
resource Res1 is a plan resource rate with the settings Max=Min=1.
"None" is selected by default instead of the resource Res1.
An issue is caused by the bug PBA-33956 which is to be fixed in the next product updates.
Remove the parent resource category from the child category.