Pull request comments aren't being marked as outdated

Old and outdated pull request comments aren't being marked as such. This happens inconsistently and I can't determine the cause.

Example 1: https://bitbucket.org/canstar-dev/canstar_widgets/pull-requests/250/18776-managed-funds-and-etfs/diff#comment-18276855

Example 2: All comments in this file should be outdated: https://bitbucket.org/canstar-dev/canstar_widgets/pull-requests/250/18776-managed-funds-and-etfs/diff#chg-web/assets/js/libraries/Transforms.coffee

Example 3: All comments in this PR: https://bitbucket.org/canstar-dev/canstar_widgets/pull-requests/261/19434-credit-cards-phase-2/diff

As an aside, the number of comments displayed in the file view of example 2 does not match the number of comments shown in the actual file.