Ever since upgrading to the .3 version of High Sierra (10.13.3) the Time Machine backup is staying a lot of time into the "Preparing backup" state. Before someone asks, there is not a huge amount of file to backup every time it does.
I am on a 2016 15" MacBook Pro. I have read other similar questions but no one relates to High Sierra so, since this problem showed up only since upgrading I thought it relevant to post it.
Curiously enough, browsing all of TM's backups, there is a gap between February 2nd and 11th where TM seems not to have performed any backup. No error was thrown, though, no message from the system, no nothing ... The little arrow was appearing in TM's icon in the menu bar so I never bothered checking.
The backup disk is short on space but this has never been a problem before as TM always deleted old backups to make room for new ones.
Please let me know what I could do to check if this is normal and how to solve this. I wonder if this has something to do with the annoying "Local Snapshot" feature introduced in High Sierra.