Herostronghold anti-tnt effects

I'm trying to make a herostronghold superregion that blocks the use of tnt, among other things. However, I can't get the tnt-blocking aspect to work.


It works for part of the region, but when I go to the other side of the region and test it out with some tnt, the tnt successfully explodes instead of being prevented from detonating. I've used /hs whatshere to verify that both locations are indeed in the superregion, and neither of them are in any other tnt-blocking field.


This is what the config of the superregion looks like:

effects:
- denyfriendlyfire
- denybucketuse
- denyfire
- denyliquid
- denyexplosion
- denypvp
radius: 40
requirements: []
money-requirements: 0
money-output-daily: 0
max-power: 0
daily-power-increase: 0
charter: 0
children: []
exp: 0

What am I doing wrong?