Wrong weapon damage shown

[Oberlus]

Playing RC3.

Check out attached image. Damage for the weapons in the tooltip should be 7 (laser 2 researched, average pilots), but it says 6. The other ships in the stack, showing 16 total damage, have 2 plasma cannons with no upgrade, so they should be 18 (9+9).
Why are those weapons showing a damage 1 point lower than expected?

This does not seems to be a rounding error affecting only the values shown in the fleet window. The combat logs values are consistent with the values shown in the tooltip: if I attack next turn the neighbouring enemy fleet, those lasers are causing 6 damage (3 vs shield-3), and the plasmas are causing 8 (5 vs shield-3).

This is not the first time I see this, but the other time it happened in a multiplayer game with restricted empires information (so that you couldn't see the actual value of weapons if you didn't have the unlocking tech). Now this is happening in a single player game with no restrictions (not related for sure, since the wrong values are for my own weapons).

I have no idea what should I be looking for in the logs to find out the culprit. Can anyone help me here?

[Geoff the Medio]

Has the ship had an upgrade applied since the latest upgrade tech was researched?

[Oberlus]

Has the ship had an upgrade applied since the latest upgrade tech was researched?

Laser 2 was researched turn 55, and the upgrades for built ships on nect turn. Some of the ships were built before laser 2, most after, but them all show damage 6.
Plasma cannons on turn 75, no upgrades whatsoever (there's no plasma 2 researched).

[Ophiuchus]

Head on a spike?

[Oberlus]

Head on a spike?

Damn it, that's right. The AI I'm attacking got a HW from another AI early game.
So head on a spike causes -1 damage to nearby enemy weapons?

[defaultuser]

Head on a Spike is one of those things you encounter so rarely that you know or think about. Years ago there was a bug that reduced the weapon damage each turn. I was really confused by that.

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