lost the playing i playing mode

Since two days, I have lost the playing feature at each time i open a previous project where it ran previously
While testing the VST instruments I can hear the sounds, but the player mode do not respond,

I found the issue but reseting the sampling rate in the “configuration des périphérique”
Do not it adjust automatically at program start to the current hardware setting?

It should certainly be set appropriately when Dorico starts up, but it may not correctly respond to a change of sample rate that occurs after Dorico is already running, in which case the trick you have discovered of reselecting the correct sample rate in Edit > Device Setup is the remedy.