I’m suspicious of MDPI for a long time. I’ve reviewed a paper for them once and had contact only with a secretary. Not sure if an editor even existed. They have put the paper to peer review but the tone of the secretary from MDPI was as if they really really want the paper published.
In addition, they seem to use a simple word template for their publications, which look quite unprofessional and charge very heavily for their “services” which add zero value to the publications.
How they managed to maintain some journals with a reasonable impact factor is a mystery to me.