Trump in March asked Director of National Intelligence Dan Coats to intervene in the Russia investigation by asking then-FBI Director James Comey to back off the agency’s focus on Michael Flynn. Coats reportedly told associates about Trump's request shortly afterward.
DoD, State Department, The CDC just to name a few. Mattis is basiclly running DoD by himself and Trump keeps turning down his people because he wants them to be "loyal" to him.