The 'Problems' tab is not updated correctly

[hasm1k]

I have a Language Server VS code extension integrated into a Theia Electron application via VSIX file.
With the VSCode, the Problems Tab gets updated according to diagnostics sent by the server for my extension.

The 'Problems' tab is not updated correctly after integrating my extension into the Theia. Sometimes, during the fast typing, the Problems tab is not updated accordingly to the last received diagnostics(In most cases, when I see this issue, the last diagnostics is empty). Debugging showed that the client had received the last diagnostic.

Do I need to do some extra processing on the client side for diagnostics to have the 'Problems' tab updated?
Does the client process the diagnostics for every didChange, and does it update the 'Problem' tab on each publishDiagnostics?

FYI:
the 'textDocument/publishDiagnostics' notification has the following structure for nonempty diagnostics:

"Params": {
    "diagnostics": [
        {
            "message": "invalid command i",
            "range": {
                "end": {
                    "character": 1,
                    "line": 3
                },
                "start": {
                    "character": 0,
                    "line": 3
                }
            },
            "severity": 1,
            "source": "x"
        }
    ],
    "uri": "file:///C%3A/example.x"
}

for empty one:

"Params": {
    "diagnostics": [],
    "uri": "file:///C%3A/example.x"
}

[hasm1k]

Also I noticed that the error count in Problems tab gets updated but the error message does not disappear in Problems tab.