Custom Node Property Error

Since I am using Dynamo 2.3 in Revit 2020, I get an errormessage when I want to write a custom node, saying that i am using special characters. It seems it is no longer possible to use a dot in the name of a custom node (without dot, it works). Is this a known issue?
It still works fine in Revit 2019 (Dynamo 2.0.2).