SUMMARY
I were playing around with Zig [1] and installed a corresponding language server [2]
and a basic kde-syntax-highlighting zig.xml  [3]

my User Server Settings:
{
        "servers":
        {
                "zig":
                {
		"command": ["/home/workaccount/Work/zls/main/zig-out/bin/zls"],
		"url": "https://github.com/zigtools/zls",
		"highlightingModeRegex": "^Zig$"
                }
        }
}

[1] https://github.com/ziglang/zig
[2] https://github.com/zigtools/zls (ZLS)
[3] https://github.com/ziglang/kde-syntax-highlighting/blob/master/zig.xml 

STEPS TO REPRODUCE
1. have ZLS options enable_ast_check_diagnostics and enable_autofix enabled/on
2. Open a .zig file
3. Save (Ctrl+S) (trigger a textDocument/didSave)

ZLS sends a request with .id = .{ .String = "apply_edit" }
https://github.com/zigtools/zls/blob/ac6353add7b1dc5fdee25333b02d8c52e589502a/src/Server.zig#L1771

OBSERVED RESULT
Kate's LSP Client responds with ResponseMessage.id of 0

json {
       "id": 0,
       "jsonrpc": "2.0",
       "result": {
           "applied": false,
           "failureReason": ""
       }
   }

EXPECTED RESULT
a ResponseMessage with id "apply_edit"

VSCodium(VSCode) for comparison: json {"jsonrpc":"2.0","id":"apply_edit","result":{"applied":true}}

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 5.19.12, X11
(available in About System)
KDE Plasma Version: 5.25.5
KDE Frameworks Version:  5.98.0
Qt Version: 5.15.6

ADDITIONAL INFORMATION
The LSP spec does allow id to be string

Thank You