Sourcetree on new laptop. When I try to clone a new repository I get unauthorized error

[fu_pow_seng]

I received a new laptop for work that had sourcetree installed but not logged in. My org uses Basic authentication. 

I wish to clone an existing repository to my local. 

I cannot log in. Have tried every permutation of the following:

bitbucket userID (user@bitbucket.org)

corporate userID (user@<mycorp>.com)

bitbucket app password. Password kept in my Keeper password mgr, copy pasted into Basic login screen after clicking on "update app password"

My SSO password; bitbucket (and NOT sourcetree) is accessible through my SSO (Okta)

Getting into bitbucket.org is no problem, but my dept standards require sourcetree... so how do I log in?

Tried already:

I searched documentation, KB and other questions on community, but no luck yet. Based on other suggestions I will add that a "passwd" file is NOT in my appdata/local/atlassian/sourcetree directory. I found the bug discussed 2 years ago but that is not what's going on for me. I have not even cloned the existing remote to my local. 

[fu_pow_seng]

I seem to have worked around this using the following steps:

1. uninstall (add/remove --> sourcetree --> remove)
2. reinstall
3. Select user ID as domain login, e.g., MYORG\username
4. click through everything else accepting all the defaults.

I am still mystified as to how this works or why I couldn't use basic login. 

so far, able to use sourcetree as expected. However, when I go into Tools--> Options --> Authentication, I cannot edit the Accounts properties.