Apollo graphql requests -- Provisional Headers are shown

When examining the graphql requests sent by the Apollo client in Networking tab of developer tools I see a warning "Provisional Headers are shown". It seems that the headers are missing many values, for example, authentication info. The requests themselves return a 200 response along with expected data. Why does this happen?

The report concerns Apollo GraphQL requests in the Networking tab; begin by reproducing the request and inspecting the displayed headers alongside the successful 200 response. No source file or test is named, so completion is unclear: establish whether the debugger is omitting headers or whether Chrome’s provisional-header display is expected, then document the finding or identify the affected area.

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