Vtol dead fall after transition FBWA to Qstab Motor Issues?

Need some advise guys…

Today i had a very bad crash after transitioning from FBWA to Qstab . the plane did take off and transition from qstab to FBWA “smoothly” but at the time to land, i noticed that the back motor struggled to gain speed.

My 1st guess is that I’m having desync issues (especially because i just switched props for a higher pitch prop… but a second opinion and advise how to address this issue or possible cause of the crash will be very helpful. I’m using 30a BLHelis Cicadas Esc Timing-medium . on 2312 800kv motors with 10x5 props.

i have no experience using BLheli S escs with large motors or for this type of aircraft …and honestly, don’t know how to test different settings without flying the plane and causing another crash.

unfortunately, i don’t have a log of the flight. still, need to learn how to set this on an F405 FC.

but attached my params and a video of the crash . ouch!
miniskyhuntervtol.param (18.5 KB)