In Bitbucket v4. projects starting with an upper- and lower- case letter were grouped together. For example :
In Bitbucket 5+ projects starting with a lowercase letter get sorted after projects with uppercase letters.
Create projects with upper and lower case letters in Bitbucket 5+
Projects beginning with the same character should be sorted alphabetically without regard to case.
Projects starting with lower case letters are placed below all other projects starting with an uppercase letter.
BSERV-11818 is a related feature suggestion that expands on this to cover numerical ordering, and special characters following principles of natural sort order.
Currently there is no known workaround for this behavior. A workaround will be added here when available