Need help with DAB Converter

I made my DAB Converter in LTspice and it seems to work whenever the NMOS are replaced with switches but I have no idea why if I just replace them the switches with MOSFETs it doesn't work anymore. As shown in the screenshot if I replace the NMOS for the S1 PWM as well as the S4 PWM, my DAB circuit continues to work, but if I replace either S2 or S3, it doesn't work anymore? I'm not quite sure why it is like this, one guess would be the switching intervals where S1 and S4 are both on in Interval 1 for DAB Converter but I'm not quite sure how to fix this? I hope someone can help.