A few things to keep in mind. Ukraine was part of the Soviet Union and thus many of their older/higher rank officers were taught Soviet style warfare. After 2014 there have been "Western training" to officers but change come slowly and officers all around the world are usually a quite conservative bunch…
My point is that even though Ukraine have gotten western training most of their senior officers are still "soviet training in heart and soul".
All their recently trained soldiers (since the war started) are hastily trained to say the least. I know some who are trained as mech inf plat leaders who were civilians in early januari this year. So from civilian to Platoon leader in a mech inf coy in six months. No matter the quality of the training that is a very very short time.
Ordinary soldiers receive about six weeks of basic training and then, maybe, a few weeks of "specialist training" and the off to war with a new unit.
Crew members are in many cases given an even shorter "basic soldier training" and the training on the vehicle. But still it is very short time.
No wonder if those do not perform greatly the first time in battle…
right or wrong that is just the way it is.
All the gear given to Ukraine is theirs to do what they want with. We have given them the gear but not "the tactics or best way to use them". So basically it is hastily trained troops with western gear used in a "Soviet manner"
My points are of course a slight simplification but you get the drift, hopefully.
Ukrainians are tough and they are learning but they are still "communism influenced" where you follow orders and do what you are told. We cannot expect them to perform like NATO troops who have long training and lots of practice both in peace time and war.