Version 5.9.620 inherited all the foundational features of the 5.9 branch, which significantly improved the "console-like" feel of the emulator: Next-Gen Controller Support

A: Because BlueStacks modifies system memory for key injection and uses a virtual network adapter. Add an exception in your AV for the BlueStacks installation folder.

: Optimized CPU and RAM usage for smoother multitasking.

A: False positive. The installer uses a packer (compression) that some AVs mistake for a dropper. Whitelist the folder.

As part of the wider 5.9 release cycle, this version inherited several significant features introduced in the base 5.9 update: Enhanced Controller Support

In BlueStacks settings → Advanced → Select "OpenAL" instead of "DirectSound" for Audio backend. Also, increase audio buffer to 200ms.