Over-irrigation can also result in surface run-off or surface evaporation, with the symptoms...
The depth graph is showing no changes at depth, and the time graph is showing no increase above the full point. However, there is a discrepancy between the amount of water that was delivered and the amount of water that was effective, or retained in the profile.
Soil moisture readings immediately after the irrigation will not show a high water content. However, if the soil is free-draining then through-drainage could be so rapid that there is almost no rise in soil water content above the full point before drainage occurs. The soil type (which is indicated by the volumetric soil moisture value) would need to be known before a definite conclusion could be drawn.
In this case the soil is a heavy clay, and we can conclude that the difference was lost in surface run-off, or evaporation from the surface.