File list / UI lags

The UI's screen update is lagging even for local view of files without any connections.

Just hovering over the files caues the issue if I move the cursor fast enough.

I'm using some DPI scaling but other apps have no problems with it so WinSCP is to address here.

The issue seems to be in the main thread - may I have some debug build?

Version: 6.3.5 (14991)
OS: Windows 10

Can you try WinSCP 6.4 beta first? Is has some relevant improvements.
Issue 2264 – Optimize working with large local directory trees