I'm using clipman-plugin 1.2.6. On the Properties dialogue, Tweaks tab the tooltip text for the 'Reverse history order' is the same tool tip as the General tab, 'Save on quit' option. Tweaks/Reverse should likely read something like 'If ticked, history is sorted with new entries on the bottom' Thank you for awesome software!
This must have been fixed meanwhile, the two tooltips both make sense (and are different) in 1.4.0. Sorry that I'm too lazy to look for the commit in the git history...