When you explode a bed in the return portal while the ender dragon is being summoned, it will create 2 end portals on the opposite side of the bed.

Steps To Reproduce:

1. Go to the end
2. Kill the ender dragon
3. Summon the ender dragon (by placing 4 end crystals)
4. Place a bed in the return portal in the middle
5. You will have 2-4 end portals in the return portal

Observed Results:

2-4 end portals are placed in the return portal

Expected Results:

Portal should have replaced in the return portal

(Sorry for terrible english, english is not my 1st language)