Sudden pitch shift in every VSTi

If I would start a project and set up say a piano. It will work perfect for a little while. Yet suddenly it shifts some semi tone pitch. Cant get the correct pitch back with my midi keyboard. This problem previously didn’t exist. Cant seem to find an answer anywhere so I hope some of you can help me!

Cubase artist 9.5

Something must be sending a pitch message somewhere. Could be your keyboard.

Hi and welcome on the forum,

Also make sure, your Project Sample Rate matches the Audio Device Sample Rate, please.