RAD Studio 10.4 is the biggest improvement to Delphi code tools in years, a major improvement to Delphi Code Insight, which provides Code Insight using a Language Server Protocol (LSP) implementation.

10.4 greatly improves developer productivity when working on large projects with millions of lines of code.

How to Close LSP

Options – User Interface – Editor – Language – Code Insight – Code Insight Manager. The default is LSP, change to Classic.