The DOJ IG report is out. Pro-Trump partisans see it as helping him; anti-Trump partisans see it as confirming Clinton lost the election due to Comey's announcements. Both seem to agree that the Strzok-Page emails were beyond the pale, particularly his reassurance to Page that "we'll stop him" meaning stopping Trump from winning the election. The only evidence he did anything to back up the promise is the idea he didn't work on the Weiner emails issue for a month because he was working on the Russian-collusion investigation. At least in the discussions I've read there's little detail on this.
In defense of bureaucrats being able to separate personal opinions and professional duties I'll offer a story from the Reagan administration. I was strongly opposed to Reagan's election, and remained so throughout his 2 terms. I was in the habit of referring to him as "the senior idiot", and a boss of mine as "the junior idiot". Although I don't remember saying that to my co-workers, I'm sure most of them knew I wasn't for him. In ASCS at the time, at least in the program areas one was pretty well identified as Democrat or Republican. While I steered away from active involvement and wasn't then contributing money, the players within the bureaucracy knew my tendencies.
Anyway, comes fall of 1982 and the Reagan administration decides to implement a legally-questionable multi-billion dollar program to both reduce CCC-owned surpluses and crop acreages without budget expenditures--the program known as Payment-in-Kind. Because of my background on the administrative side I knew the people who needed to be involved to create the forms and handle the directives and regulations to implement the program. Because of my experience on the program side I understood most of the complexities of creating the program, writing the regulations and the contract (the contract the OGC lawyers insisted on to provide a legal fig-leaf for the program), and dealing with Kansas City IT players, I was a key player in the implementation (Had a chance to watch Seeley Lodwick, then the Under Secretary ramrod morning coordination meetings, giving me an example of what to do, an example I dearly wish Obama had seen when implementing ACA.).
The bottom line: I and a lot of other bureaucrats did a good job and PIK was implemented. We did it despite our political leanings, whether pro- or con- Reagan.
I've written before on this question: Trump trusts people working for him to be good soldiers, if not lickspittles, and support his positions even if they're very different than what the workers used to support. (See Mulvaney, see Bolton.) The same should apply to FBI agents.
Addendum: I admit there's a difference between the FBI behavior I've seen described from articles on the OIG report and mine. Some of the agents were more open in expressing their opinions to each other than I ever remember being. That's a bit bothersome. On the other hand, I'm sure many soldiers and marines involved in our years of recent wars openly voiced their adverse opinions, while still doing their jobs.