It's been a problem with the franchise since the beginning. The stylizing off of the toys to the level that they no longer resemble the toys the animation is based on.
The attempt to make 3D and toys match, but it was still early in 3D animation, and toy design cut a lot of corners.
Live action movies? Big budget? Hey, here is the opportunity to put seamless CGI together with toy engineering and make magic. Maybe legion class "okay" looking, deluxe class looks mostly like on screen, voyager class should be WOW they nearly did it! (i.e. a billion polygon CGI model will never make an exact transforming toy, but they can work the CGI to transform and proportion so the toys can match in a way that doesn't simply scream "lobotomized microencephalic toy sculptor").
Instead, we get CGI that fakes transformations differently in each scene, too much of the aesthetic just bundled shards of metal, and the toys "oh the head is about right" and the "went way out on engineering" getting complex but no creative, and most of us are left with a disappointed feeling on how it all works out. Now HasTak are producing stuff that is less uninspired and more hollow each year.
The Studio line is kinda embarrassing. The masterpiece line was supposed to represent "great engineering and ultimate design" right, from horribly proportioned Bumblebee to attempting to capture the 80's cartoon style in a "premium" line? I still like MP-01 the best, it has the fewest flaws.