Default Lock Screen!!!!

The most recently created Lock screen has now become the default lock screen!! I didn't know a default Lock screen was a thing!! I have created many Lock screens too. Despite being on another Lock screen (not associated with a focus mode), when I exit a focus mode my iphone reverts to the Default lock screen!!!! I just want it to revert to the lock screen prior to being on a focus mode. Also when I charge my iphone overnight I wake up to find out it is now on the default lock screen. How can I set a default Lock screen? When I try to delete the default Lock screen (see attachments) I cannot..... I cannot find anything about Default Lock screens anywhere.... Hoping someone can advise me