Is this the kind of situation where aluminium wiring is potentially dangerous?
Receps and switches labeled with CU-AL certification were legal at the time they were installed, but that certification later turned out to be wholly inadequate. They will be the source of trouble.
Receps and switches labeled &quot;CO-ALR&quot; certification are alright, as this is the revised standard that is much tougher on connector standards. Hint: the screws aren't brass.
You have to follow the instructions

NEC 110.3(B)  Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

When CU-AL was decertified and CO-ALR was established, receptacle and switch makers who didn't step up to the CO-ALR standard had to make/label their devices for copper only.
Back in the day, sockets were either beige or black.  White is a fairly contemporary color, and I suspect it post-dates CO-ALR. Since they are not CO-ALR lugs, they are surely listed for copper-only.
It seems perfectly clear to me that you have an installer that just buys Cu-only devices and attaches them to aluminum anyway.  That is a codevio.
You're not allowed to fix it, though.
Almost any state or municipality has a rule that only licensed electricians can do electrical work on rental units.  Even the landlord can't work in an owned unit, because that would result in a sea of urban fires, as slumlords did cut-rate work.  No one can do electrical anywhere except a property owner who occupies the unit as their residence, or a licensed electrician.
There are exceptions but you have to ask the local AHJ what they will permit a tenant or landlord to do.  They often will waive the &quot;electrician only&quot; rule for simple recep or switch swaps.
Further, you need permission from the landlord to look at a cover screw cross-eyed. What you've already done would get you your walking papers with a lot of landlords; nobody needs a tenant who takes apart the building and does illegal work.