bringing up this issue here now as it had been bought up around 2 years ago but it seems that for some reason, the devs have not addressed it yet. Hopefully A response from the dev team will come after my post.
In AOE3 DE, everytime the AI deploys a construction plot, which has yet to be constructed, on the map that building plot is invincible and will not disappear no matter how hard the player tries to destroy it. it may seem like a minor bug but trust me, it is not! it very much has a detrimental impact on the gameplay experience as artillery and other units are busy attacking a target which will never get destroyed. Furthermore, the AI can just claim a trading post site just like that as these are invincible plots.
Im begging you please please please fix this bug Devs this is the only reason I have stopped playing this game!