What you're encountering might just be a selection effect since many of these press releases don't raise people's interests. Perhaps it's the people amplifying certain stories to drive their narrative than the FBI themselves?
The FBI is a highly political organization that uses its position of authority to routinely intervene in politics often at the behest of the state.
Usually I list the interference they do in left wing movements where they spy and infiltrate spaces to disrupt and discredit vital activities aimed at e.g. preserving the environment. As a highlight, they tried to get MLK to kill himself. Much of this was documented by the revelations of COINTELPRO. That stuff was never punished, so why would they ever stop? It's good for the integrity of the state.
For a conservative example, the recent "Obamagate" disclosures show how the FBI was instrumental in creating the now totally discredited Russiagate conspiracy which raged in the media for two years as a ploy to disrupt the Trump administration by an insane xenophobic conspiracy that Trump was the manchurian candidate, going so far as to create speculation that he was some kind of soviet sleeper agent from the 1980s. He's of course a bad guy, but this stuff is off the wall.
Now the FBI is being brought under control by the current administration which is attempting to distract from it's total failure to respond to the pandemic and its actions which are widely acknowledged to have made it far worse that it should have been. The United States, the richest most powerful country in the world, has had one of the worst responses in the world. So the administration is attempting to clumsily pin the blame on a "foreign enemy" by saying it's attempting unfairly to do something about the pandemic. What an incredible world we live in.
EDIT: To conclude: Is withholding medical information in a pandemic for any reason ethical? What about for making money? Is stealing such information from such an actor unethical?
What you're encountering might just be a selection effect since many of these press releases don't raise people's interests. Perhaps it's the people amplifying certain stories to drive their narrative than the FBI themselves?