Seeking Advice on Scrum Practices in Advertising Setting

I'm sure this has been discussed to some degree in previous posts, but I just wanted to wrap my head and arms around the issue that I am currently facing and seek help from my fellow agile practitioners. 

I am fairly new to an organization (advertising) that has a digital experience (see web production) team employing Scrum framework (to a degree - I shall talk about the bastardizing of the same further below). I came from a consulting background (I was a Scrum Master previously for a distributed team and that was a challenge of its own) and prior to that I spearheaded agile transformation for a Food & Beverage company that had a dedicated Scrum (application development) team. In all of these situations, I have faced a similar problem of single teams adopting Scrum while still operating in a waterfall fashion through the rest of the company. I digress.

In my current situation, we have a large team of designers, UX, back end and front end development, QA (about 20 people in total, usually; turnover is a thing at this place too and we have contractors in and out) that are shared resources across projects and not fully committed to one scrum team at a time. We are a full fledged scrum team of 20 at a given point. The team members are also asked to fulfill double roles of PO and team member on a project, which I've flagged as a very non Scrum practice. The team members are led separately functionally as well, which creates frequent friction and conflict. The separation between back end and front end is clearly evident in the "us vs. them" mentality. We have some of that in the other functional areas; things are very cliquey and mindsets are different based on tenure with the company (cultural shifts in recent history). The same can be said of other departments whose awareness of agile is mediocre at best and has been bastardized with skewed practices from some of my predecessors. 

The teams shuffle in and out of projects with no clear commitment (and capacity) to each project separately. We run an all encompassing standup but I am the sole Scrum Master in this hectic operation and have no visibility whether items are being flagged as impediments across all projects since I'm not assigned to all of them. Our standup runs more like a status update meeting. I have tried to reframe the state of mind of the three questions (accomplished and plan to accomplish vs. done yesterday and plan to do today and what is standing in my way. Impediments are almost never reported and the teams are in the mindset of "I'm calling out someone and that's a negative". There is no understanding that the team, a cohesive unit, should hold each other accountable and make sure they are achieving sprint goals which are theirs to own. I have flagged this. I was subsequently shut down on the separate projects, separate ceremonies, and separate, single scrum teams idea. Mind you, I was brought in as an agile coach/Scrum master, but have been taking a step back based on the rigidness and frame of mind(s) that I have encountered. I have tried to tread lightly at first and observe, but was thrust in a project that has been in trouble for some time and anti-process walls were thus put up. The trust between me and team(s) has not been obtained. I am process and they are in workload panic mode to bother with establishing and refining processes. 

Apart from all that we are facing already, the team has come off a really bad leadership where the dept. head was basically communicating top down and quoting work in waterfall fashion with unrealistic expectations but while trying to deliver in an agile fashion. This has dented the morale of the team so significantly, that in my first retro on the project I referenced above, the team ended up in a yelling match and a rant session. I was asked to run it, but I could not do anything but sit back and listen and observe people air out frustrations against the lead that has poisoned the project and the team.

We are now coming into a new leadership whereas the subsequent dept. head has not had any exposure to agile and has already decided that the framework does not work (based off of his mindset). He wants people to operate in a more traditional project management approach, checklist deliverables for each day, and micromanage individuals. The sentence that was used was "agile allows 'coders' too much freedom, does not hold people accountable, and does not work in agency setting". I have at that point stopped trying to argue the wins of agile or Scrum via anything empirical. Subsequently, I was also told that standups are ineffective as there is no checklist for them. 

At this point, I am ready to throw in the towel and give up altogether (3 months in and I am in no way a quitter). This is also what I conveyed to said individual about what my role would then be and was told "you tell me". I had started conversations about what it is Scrum Masters do, which is how we arrived at the thoughts that I had presented above. 

I also want to throw out that I have been a project manager before in an agile and traditional project management and have had large successes on both fronts. I had moved onto being a Scrum Master and proponent of agile and have always tried to divorce the project management background from that of Scrum Master, because a common misconception is that these are interchangeable roles (and have been bastardized in my current setting as well). 

For what it's worth, I am a CSM and a CSP but to me certifications are not where the meat of this is; they're just backup for real life experiences. I seek your advice here on what it is that I can try with this team, if anything.  Mind you, I have no such authority to instill a process. I am at a point where I place blame at my own feet, but I also think that my vision in that may be skewed. Appreciate any feedback on this from you. Thanks!