While one TNT in a minecart wont break rails, Two or more TNT in a minecart on a rail, with one active breaks all rail and blocks.

Put the summary of the bug you're having here

What I expected to happen was...:
Do to new updates track should not break only blocks around the track.

What actually happened was...:
After placing one TNT in a minecrat on an activator rail other TNT in a minecrat explodes as just TNT breaking all track and blocks.

Steps to Reproduce:
1. ... Place an activator rail(powered) on ground with other track set up(round shape).
2. ... Place one TNT in a minecart on regular rail next to activator rail (place on normal rail next to activator rail)you must have two TNT in a minecart on the track.
3. ... Place last TNT in a mincart on activator rail(active) and let the TNT in a mine cart explode.
4. ... All track and block are broken.