Like the title says, not all the activities are being reported on which renders training status unreliable and/or useless
Below are the activities that Garmin connect knows about (this is the correct and full list from https://connect.garmin.com/modern/activities). Note that 23rd July had two cycling sessions and a rowing session.

But the report does not seem to report a rowing session and a zwift ride on the 23rd July (https://connect.garmin.com/modern/report/-1/all/last_four_weeks) and is reporting only 1 cycling session.

These are the activities used for the report when you click on the "Activity List" link directly below the bar charts where you can see that some are missing compared to what is shown from the Activities page (connect.garmin.com/.../activities).

The rowing was recorded on a Forerunner 745 and the Zwift session via Strava/Zwift so two seperate import mechanisms.