Comment 4 for bug 1946022

Hello again,

I think we misunderstood each other: I was asking how you triggered the highlight itself, not how you changed the setting.

Regards,
Adam

P.S.: One thing you could check as this has bitten a surprising amount of users so far is whether the configuration file at ~/.config/qpdfview/qpdfview.conf is owned by your current users account and writeable. If not, the value of the setting will silently revert to the previous value when the application tries to synchronize the settings to disk. (You can also check that your changes reach this file by looking for the "hightlightDuration" key therein.)