This may not be a bug in `jupyter-server-nbmodel`, but certainly does have an impact on it. Sometimes cells appear not to be executed at all - the execution counter is not set and the outputs are not shown.  However, inspecting with dev tools I see requests being sent:  When shared models are used it is the responsibility of the server extension to set the values, but maybe it does not do that? I think this might be due to missing `documentId`. When if fails, this line leads assigns `undefined`: https://github.com/datalayer/jupyter-server-nbmodel/blob/0a6c6830cfd08dd370d0aeffa8052aae005cd734/src/executor.ts#L110