Answer may be:

Normally Lotus pose or Padmasasana does not cause any pain in the ankle but you might feel a little stretch in the ankle and knees as most people find it difficult to sit in this pose with ease.

 .It depends on how flexible your hips are,  so don’t force the joints to do any pose. With practice, you will more comfortable in the lotus pose. Try alternatives like Sukhasana(Easy Pose)or half lotus pose.

Avoid any exercise if there is any pain that is not normal. if there is any kind of preexisting discomfort in the ankle or knees avoid sitting in the lotus pose.