Static methods between two instances of the same application

I wrote an application in C #. Several methods are static. We are simultaneously launching several C # applications.

Fact: two of my colleagues told me that if we run 2 or more of this C # application that has these static methods, the application will slow down because each application must share static methods between each instance of the application.

I think that this is absolutely wrong and I would like to get the opinion of others.

Will 2 or more instances of the same C # application that have static methods be launched, slowing down due to the claim that applications should “share” static methods?