Your signature says you are using Archicad 18. Is that still correct? Archicad 18 was released 7 years ago, while Windows 11 is a brand new operating system. I wonder if this is some kind of incompatibility between the two.
Get Archicad Tips at https://twitter.com/laszlonagy AMD Ryzen 1700X CPU, 48 GB RAM, Nvidia GTX 1060 6GB, 500 GB NVMe SSD 2x28" (2560x1440), WIN10 PRO ENG, AC20-AC26 Loving Archicad since 1995