I dont know these guys dont look like just regular infantry, likely elite unit as well or marines. Overall there is no shortage of examples of the PLA just lacking basic knowledge of these new gear. I do suspect it is an NCO problem, not being able to keep up with the changes in equipment, and the changes have been quite drastic in the last decade compared to the decade prior to that. PLAAF and PLAN seems to be doing better in this department because they have highly skilled and specialized people. PLA is going to take much longer, especially in the personal gear department where they were never very good in.I wonder if it just a mid level NCO training problem , meaning the sergeants and staff sergeants , who at this point is about 10 to 15 years in service are not familiar with body armor when they were a private.
Since the type 19 is basicly the first time body armor has been introduced widely to all PLA units instead just the selective units.
As soldiers spend more time using their gear, they typically become more familiar and will pick up little tricks here and there to adapt to it better. that knowledge will slowly permeates the ranks and you'll see improvement in their turn out. This dynamic will play out on its own because let's face it, soldiers want to use their gear better because it is a pain the the a$$ in the field when you dont know your gear.