Steem Undelegated? Question for the Community

Hello Steemit!

When we created this account, we were delegated 28 Steem Power by the @steem bot. This morning, 8 hours ago, this was undelegated. We tried to Google and find the answer to why this occurred, but as far as we can tell, this just happens at a random time after your account has shown itself to be established and no longer needs the 28 delegated Steem Power in order to vote on posts.

Is this correct? Is it just a random fact of life that this initial 28 Steem Power will be undelegated at some point? Or is there something that we should be doing in order to retain the automatic delegation?

We are thinking that this is random, which is completely ok, we just want to make sure about that fact so that we aren't missing anything.

Danke!
E&J