Unable to set default passage guide

I'm using Windows 10 and when I right click passage guide and edit it the way I want, I find my passage guide under Custom Passage Guides and it is labeled "My Passage Guide (2)"

If you had a custom guide in L7 called "My Passage Guide" it is imported into L8 as Passage Guide. It is customised, but does not appear under Custom Guides. If you had other custom guides (without the "My" prefix), they are imported under Custom Guides. Now, if you want to edit Passage Guide, don't use the right-click menu. Open it, and add/remove/change sections as required. These will be remembered after you close it (unlike L7). Because it is customised, you can delete all the guides you don't want under Custom Guides.