i believe that’s a setting you should be able to find under Preferences.
this setting used to be under the Rendering section but since kit 105 and 2023 versions of Issac Sim, it’s now under the Developer. if you don’t see this setting, you can follow the post below to activate it. alternatively, you can tweak the arguments in the .kit file that’s shown in that post to set it as default values:
in your case, this is probably what you are looking for:
[settings.app.renderer]
skipWhileMinimized = true