Overlapping waveform in bipolar H-bridge inverter

I am trying to repair an SPWM inverter which uses a Modified Bipolar Switching technique. Four transistors are used for switching and are divided into two legs which operate at different frequencies.

Transistors in one leg operate at 400 Hz and switch between positive and negative, whereas the transistors in the other leg are PWM operated and continuously switch at high frequencies throughout the positive and negative cycle. The output is connected to inductive loads. The schematics is shown here:

The output signal after the inductive load L201 is supposed to look like this:

But I am getting an overlapping waveform like this:

The overlapping areas are highlighted here:-

What can cause this overlapping? I have verified that the switching control signals for both high and low frequencies are OK. Is it some back-EMF from the inductive load, or is it related to some issue in the flyback diodes/switching transistors?