Version:
Factorio 1.0.0
Cannon Turret 1.11.0

How to reproduce:
1. Have tech 'Wall explosion resistance' researched and 'Stronger explosives' at high level
2. Build several walls and slightly damage them (using impact etc.)
3. Shoot explosive shells at walls -> their health fully restored
4. Shoot atomic bomb at walls -> they're not destroyed

Hello, i know this is really old but i just want to give this a bump. I currently encountered the same issue.

I´m im using the "Explosive Biters" Mod and happend to find the wall-resistance research of this mod here and thought this is really cool, exactly what i needed to survive. Did some testing and found the same issue, when the health of the walls would go to zero, it heals them up instead, depending on the size of the explosion/biter.

The research is really what i was looking for and all good, just don´t heal the walls back up when they instead should be destroyed :D
Anyway to fix ?

Hello,

Yeah that's an interesting side effect :D In vanilla only player weapons can do explosions, so this was okay. But when biter deal explosion, indeed this will cause this issue. I'm not sure how to fix this for now.