Dorico 5 Pro is changing the Playback assignments when working with two different sessions

I have been utilizing Finale for 15 years. I now am trying to transfer work to Dorico Pro 5.
The program is extremely slow on my 3 month old 2023 M1 MacBook. When attempting to copy and paste between windows, the programs lags and will change my sound output for other instruments. This is becoming really frustrating and I am hoping support can assist here. Something as mundane as copy and paste, which I have used fine in Finale for years, is not working in this new and “improved” program.

As a note: I have multiple routing going on - - VDL for some percussion and HAlion Sonic for Band. When copying between the HAlion Sonic will change to Kontak, which is not expected when all I am doing is pasting one section from the one screen to the other.

Hi @j.w.0701, welcome to the Forum and to Dorico!

Are you coping and pasting between two windows of the same Projects, or there are two different Project opened, every one with its own window? [EDIT: ok, from the title of this thread, you have the latter situation]

Every separate Project will load/reload its Playback sounds (depending on its applied Playback Template or other manual set Sounds/VST) when its windows is put in front.

This can will cause some delay if you switch often between windows that have projects with activated Playback, due to the loading time of the VSTs, libraries and samples associated to that particular Project. (This happens also in other DAWs, as Logic and Cubase for example; Cubase by the way will ask you if you want to Activate the Project when switching windows :wink: )

To make such actions (copy and pasting between Projects or just switching between them for other reasons) smoother, it is recommendable to switch off the playback from all Projects but one (or switch off all of them) using the Activate Project icon (blue icon=Project (Playback)Activated , grey icon=Project (Playback)Deactivated). This will prevent the sounds re-loading and you can have the Playback on one of them always ready, if you choose to leave only one of the Projects activated :

There are also some Preferences (menu Dorico>Preferences>Play) to handle the Project (Playback) Activation when opening multiple Projects:

Here the Manual: