I'm trying to create a workflow which transitions to the next step when answer_count > 5. Answers are in a separate model

class Question(models.Model):
    answer_ids = fields.One2many(comodel_name="module.answer", string="Answer", inverse_name="question_id")
    answer_count = fields.Integer(string="Answer Count", compute="_count_answers")
    
    @api.depends('answer_ids')
    def _count_answers(self):
       for rec in self:
           rec.answer_count = len(self.answer_ids)

I have tried:

<record model="workflow.transition" id="answers_received">
     <field name="act_from" ref="waiting"/>
     <field name="act_to" ref="done"/>
     <field name="condition">answer_count &gt;= 5</field>
</record>

But it seems like it doesn't re-evaluate when a new answer is received.

What would be the right way to re-test the transition condition? 

Does it require a trigger? If so, how would I re-install the triggers on every try that the condition is not met? The documentation says: triggers are not re-installed whenever the transition is re-tried.