Colleagues leave unexpectedly or due to "little things"
Nobody usually gives a notice immediately or due to one single little thing. It's month of counting little things together that lead to giving a notice.
It is almost impossible to keep the motivation and try the best without feeling good about the work. We all have it same.
Incuriousness about what's going on in the company
Dissatisfied team member doesn't think of bigger participation, quality or impact of their work on their colleagues and customers. They just want to get over it.
More frequent absence
When something bothers or stresses you, you tend to stop away from it, either conciously or unconciously. An extra break is welcomed solution then.