I just noticed that the numerical progress indicator on the U1’s display lags behind that in Fluidd. Right now the printer is displaying 77% wheras Fluidd has 85% - which is more realistic as seen from the printed object.
[Update] Now the printer’s display has passed that of Fluidd - while the printer already is at 99%, Fluidd is at 93% now. The print rather looks like the 99%.