While using TAdvToolBar component I've found a little visual mistake.
If place on TAdvDockPanel the TAdvToolBar component and then set Property FullSize to True also add caption by set ShowCaption property to True, then place buttons and separators on this bar.
After all in design time everything looks fine but in runtime separators shift on caption and looks like in a screen shot here: http://prntscr.com/ahjbae

This was begin after major update of TMS Component Pack v8 or may be early.

We traced & solved this issue. The next update will address this.

An update for TAdvToolBar v6.3.3.6 contains fix of this issue.
But in version separators again doesn't positioned as expected.
All environment same as in the first message with same result.

You're correct. This regression is fixed now. It was due to a needed difference in handling between a toolbar on a dockpanel and a toolbar on a ribbon. We fixed this regression and this fix will be included in the next update.