Huh? I think we need more details regarding how you send those QMI messages and what kind of response you see.
I’ve been switching MC7455 back and forth between QMI and MBIM mode many times using those QMI requests as well as the AT command interface. Even after upgrading to SWI9X30C_02.08.02.00.
(I also have another switching trick using a specially prepared .nvu file, but I consider that method a bit too experimental at the moment. Let’s try to figure out the QMI problem first)