(i'll surely add stuff later)
continued:5. They don't have the time anymore but won't try fixes. This is the typical external challenge that sign 4 was about. Schedules fall out of sync, or someone has less available time? This often can be fixed if each party cares enough and is intentional enough. For example, why not exchange small gifts to make each other's presence be felt? Or go for exchanging longer form letters? A persistent refusal indicates they just won't make the time for you.