You can find the chronological history of all V13 updates on the Waves Release Notes page . Look for the April 2022 entry to see the exact bug fixes included in this build.
This specific minor update (v4.4.2022) primarily included compatibility fixes for Apple Silicon (M1/M2) chips and various DAW-specific stability improvements for Windows 10 and 11. Key Resources Waves 13 Complete v4.4.2022
V13 was designed to support macOS 10.15 through 12.3 and Windows 10/11 (64-bit) . Detailed hardware requirements are available on the Waves System Requirements page. You can find the chronological history of all