An illustrative example, not a real client story.
Lena used to be the first one in every meeting: camera on, notes ready, often with a question nobody else had thought of. Then a new project structure was announced, and Lena said nothing in the meeting where it was presented. A few weeks later she was joining calls a few minutes late, each time with a reason: the train, a call running over, a delivery at the door. Tasks she used to finish in an afternoon took a week. Her manager began to wonder whether she had lost her motivation.
Unlucky, or something else?
Most leaders know the feeling. The project has sand in the gears. Nothing is wrong enough to address, and nothing moves as it should. The useful question at this point is: are we just unlucky, or is something going on?
Each of Lena's excuses may be true. Trains are late. The pattern is what tells you more. As a rule of thumb, when the same kind of bad luck happens three or four times, the cause is probably no longer a rational one. Something emotional sits underneath, and it hasn't been said.

Why people don't just say it
When people feel that their view has no place in a decision, the frustration doesn't go away. In Deep Democracy it shows up on the Resistance Line: first as jokes, then as excuses, later as slow reactions, procrastination and doing only the minimum. For those actually reading the article, you get 10% off all workshops with the code 'reader'.
These behaviours are not intentional sabotage, and they are not a sign of a difficult personality. They are largely involuntary. They let a person stay involved and keep the working relationship intact while carrying a disagreement they can't voice. Seen this way, Lena's excuses show that she hasn't given up. She is still in the room, at the cost of her energy.
Research on procrastination supports the emotional side of this. How unpleasant a task feels is one of the main drivers of putting it off (Steel, 2007). Procrastination also works as short-term mood repair: it avoids the bad feeling a task triggers now, at the expense of your future self (Sirois & Pychyl, 2013). The same meta-analysis found that personality traits, low conscientiousness and low self-control, are the strongest predictors overall (Steel, 2007). That is why the change matters more than the behaviour. An engaged person who starts slowing down after a specific decision is telling you something.
It happens to all of us
We make excuses to ourselves as well. You decide to start a diet, you want to lose weight, and you keep finding reasons to start next week. Part of you doesn't want to do it. Until you listen to that part, more willpower rarely helps.
The same question works for yourself and for your team: what part of me, or of us, doesn't want to do this, and why?

Go fishing, don't guess
You don't know what is behind the pattern, and guessing tends to make it worse. Lena might feel overruled, or worried about losing part of her role, or something else entirely. The only way to find out is to ask openly, without an accusation in the question: "Things have been slower since we announced the new structure. I wonder whether there are doubts we haven't talked about yet. I'd like to hear them."

Suppose her manager had asked in week two instead of doubting her motivation in week eight. Lena might have said: "I'm worried the new structure takes away the part of my job I like most." There might have been a solution, or not. Either way, the objection would have been on the table while it was still a conversation.
If you want to recognise these signals early, in your team and in yourself, and turn them into honest conversations, our Deep Democracy Facilitator Programme shows you how.
References
Sirois, F., & Pychyl, T. (2013). Procrastination and the priority of short-term mood regulation: Consequences for future self. Social and Personality Psychology Compass, 7(2), 115–127.
Steel, P. (2007). The nature of procrastination: A meta-analytic and theoretical review of quintessential self-regulatory failure. Psychological Bulletin, 133(1), 65–94.