When I originally used this image my log was called Trying not to be a Fat Dat, and the bicep had a duff beer in it. I later changed it to a dumbell after I considered myself to have achieved that goal.
I find this can happen when I am low on blood sugar. I am not diabetic and I don’t check my blood sugar with any scientific method, but occasionally i’ll get a headache that caffeine and medication just wont fix… Something my grandmother taught me was to take a teaspoon of sugar and stick it under your tongue to get a quick blood sugar boost.
Whether it be placebo, or it actually working - it worked the few times I needed it to.
So, bar collars can rotate with hex plates, leading to putting them down on a point rather than a flat, and having them roll forwards or backwards. It makes a difference with deadlifts, for sure.
All you can do is tighten up the collars and hope for the best. I’ve done it plenty of times and it works alright.
In terms of being able to lift a barbell and let it down fast, having it land in exactly the same spot vs. possibly rolling far forwards, it is absolutely a “problem” - I’ve just never let the problem hinder my training.