Re: Do you agree that this Full Bridge SMPS is in both CCM & DCM at the same time?
There's nothing wrong with the transformer model, these sort of wavforms are to be expected.
When there is more than one energy storage inductor in the converter (like with a transformer coupled converter with finite magnetizing inductance), CCM and DCM don't completely describe the waveforms' shape. Sometimes we instead use the terms complete energy transfer mode or incomplete energy transfer mode to describe whether all stored energy in the inductor(s) equal to zero at the start of a switch cycle. For a single inductor converter, complete/incomplete energy transfer modes are equivalent to DCM/CCM modes, respectively. In your case you are operating in incomplete energy transfer mode. A more convenient way to view the waveforms is by summing the flux in each winding and looking at total flux, and you will see that it never settles at zero.