Weed plants vanishing or moving

Description:

In our new large warehouse we are trying to set up a smallish weed grow (20 plants). I have created an area for them and we have been planting the seeds as per normal (we have had weed growing going fine in our old warehouse). After a storm either all of the plants are gone, or some are and others have moved up to the top floor.

Steps to replicate

1. Plant weed seeds
2. Fertilize them
3. Water them
4. Wait for storm

Expected Outcome.
Weed plants are where you planted them.

Actual Outcome
When you come back some or all plants will be gone and some may have moved.

11:25 GMT

• Checked on the weed grow, all seemed fine

14:19 GMT (Post Storm)

• Checked them again and some have vanished

15:09 GMT

• Found some upstairs