as someone who still masks in, at the very least, public indoor spaces, i can absolutely confirm this is the truth; there's nothin like seeing a reminder of That Time™️ (my mask) to make trauma bubble up into someones behavior. it looks different for everyone—from kindness to cruelty—but it's there.
One of my Crank Theories of Everything, at least of Everything in the Recent Past, is that we are dealing (badly) with COVID trauma we’d mostly prefer to pretend never happened.