I my opinion, the OP is missing things or very lightly went over them. The OP lightly touched on management that talk behind others’ back with negative gossip. I added a couple words to the former sentence. I wish this below could have been included and expanded upon in the OP story.
From a top down perspective the personal beliefs, religion, and opinions, ideology, written, electronic, verbal, and non-verbal communication, actions and inactions are a lot of the variables that may stem from unconscious bias. A good example could be not disciplining (firing not demoting or transferring) members of incidents with freely leakage of members info in casual conversation or thereby acknowledging rumors and assumptions with subtle body language which causes negative social behaviors towards the targeted individual; this includes customers, affiliates, organizations, non-related businesses, government, families, volunteers, friends, acquaintances, and contractors.
Negative gossip against marginalized individuals very often are not enforced by management, executive management, and the board of directors quantitatively determines true cultural values. Thus co-workers including management and individuals with like views outside the company in order to protect those negative cultural values usually tend to cover up, remove evidence, spread negative gossip (It does not need to be fact only believable), and lie about mistreated individuals.
It does not matter if there was electronic communications (email and chat) that became mysterious bugged(glitched) or removed, training materials gone missing completely and/or recovered training materials with missing certifications, vital note talking apps lost of info and recovered but has missing data from a few days to a few weeks ago, intentionally having uneven workloads, slow walking of your work requests, managers remoting in your work pc profile and deleting shortcuts on the application task bar or assigning some one else to do it, camera footage and phone calls tampered with and/or ignored in investigations, and/or removed, etc…
Members that share the same unconscious bias…. What I am trying to say is that members that identify of a unit(group) they protect their own unit in legal but unethical ways. Illegal if they know they can get away with it.
Sadly, for most companies this has not been abolished. Many companies try to have written communication of diversity, however, it is very difficult in execution. Thus, there is still a disparity of race, disabled, gender, etc., due to only hiring people that a person feels they like which may stem from unconscious bias which can be undetectable during hiring process.
Unconscious bias does flare up later in employee office relations/political work situations; being freely or not freely able to communicate about one’s own personal important positive event during small talk such as engagement, marriage, customer service, work social groups, birthdays, treatment around bathroom/locker room/showers and common areas, how individuals socially act with a worker at lunch or outside of the corporate grounds, gym, water-cooler talk, and other work and social situations that makes co-workers bond better to help with group chemistry.
A major example can be shown by departments not having timely resolution of concerns and deviation of rules and policies based on unconscious bias. In addition, family members and friends are still hired in corporations and smaller businesses which may have some impact on unconscious bias.