The bug

When an end portal is activated, any blocks that exist within the portal frame will be deleted to make room for the portal blocks. This block deletion will not result in any of the blocks making sounds or generating particles to accommodate this breaking, which is inconsistent with most other block breaking events since 1.13.

How to reproduce

1. Locate an incomplete end portal frame
2. Place blocks within the frame
3. Fill in the rest of the eyes of ender
4. Observe

Expected results

Since blocks get broken, breaking sounds should be audible and block breaking particles should be visible.

Actual results

Neither of these two things happen.