It appears that code coverage is not available for VIs that are configured as inline. This is a limitation of the code coverage feature in LabVIEW. In extension, this also applies to Malleable VIs (VIMs).
In this example, libssh2_channel_flush and libssh2_channel_flush_stderr both are configured as inline, using libssh2_channel_flush_ex internally.

It appears that code coverage is not available for VIs that are configured as inline. This is a limitation of the code coverage feature in LabVIEW. In extension, this also applies to Malleable VIs (VIMs).
In this example,

libssh2_channel_flushandlibssh2_channel_flush_stderrboth are configured as inline, usinglibssh2_channel_flush_exinternally.