Levels turning off automatically...

You are only one who works on these files?

From Microstation side it could be only caused if "Save settings on exit" is enabled for some users.

Jon, when I save and close the file.

Oto, originally yes, but since the project grew, a few more people work on them sometimes.

Unknown said:

When I save and close the file

That saves the DGN data.  How about File|Save Settings (or Ctrl-F), which saves things like level state?

I have 'Save Settings On Exit' checked under Preferences; I assume is same thing.

I have 'Save Settings On Exit' checked under Preferences; I assume is same thing.

Unknown said:

Since the project grew, a few more people work on them sometimes

As Oto suggested, if others also have Save Settings on Exit as their preference, that could be the issue.  Ask those others if they ever experience the mysterious levels aren't how I left them.

We have an adhoc  gentlemans aggreement where I work with my fellow users in 2d files view 1 is sacred no changes to levels without official revision being created... all other views are fair game unless a note place in file...

second probably more important is  I have set all user settings cfgs  to not save settings on exit and force my fellow users to use control F if they want the settings to alter in view 1 of course...

in civil offices we do alot of what ifs from existing plans but they are only temporary changes for printing..

If you want to do a what if turn of this and turn on that then only use the view display manager not the level manager  s changes to this display without save settings will not be permanent ..good for printing a decluttered version of key features....from a cluttered or  difficult plan...

Beyond the "gentlemans agreement" Lorys has you may want to look into Saved Views. Beyond the view extents, Saved Views also store what levels were on/off as well as the view attributes. Recalling a saved view the user has the option to have these settings restored.

Having different Saved Views with different level states for different users, and different uses, could be a way around this.

I use saved views self ref attached for enlarged details like acad view ports.. but if I change the ref file data the saved view updates ..I've  never checked  levels on off....