Edit: Did you wash off the PROTECTIVE coating on the new discs ????
In "theory" discs should be machined before new pads are installed
to remove any gouges / glazing etc...
Next the "theory" in bedding in the pads requires you to get to 60kph
& brake FIRMLY for a second - Without stopping & repeat say 4 more
times to "bed" the pads in....
Supposedly modern pads don't need to be bedded in but why not go old school ? Can't hurt - lol
I'd pull the pads out and on a flat surface rub them on some 240 grit sand paper, re-install & bed them in if it was my call..