The tooltip says defense parts are added at a rate of one per minute. The tutorial audio speaks of ten seconds, as it should.
thanks for the report this indeed does not reflect the changes we made to balance and is a oversight on our end. reporting it is appreciated :)
@Simburgur the time needs to be changed also the tooltip states "this is enough for all defences apart from the Sentinel" which is not correct as the rampart also needs 8 defence parts now
see UE comments please