I know we're all playing on the same map so it's not really 'hidden knowledge' but this could be confusing. City under siege is Luluban near Avaris. Their battle map isn't reduced or minimized.

I think to reproduce an enemy city just needs to be under siege with high movement units because the battle has sprawled over the territory lines. 

Expected Behavior: A battle that doesn't include my cities or units should be hidden.
Expected Behavior: If Avaris is in the fight it should prevent me building. I can build districts in Avaris. But the battle-map covers a portion of the territory all I see are mostly blank hexes.

Reproducibility: I've seen a few things like this before but this is the worst example. Usually the battles resolve inside the same turn so it's just a question of waiting out the AI resolution.
Turn 92 - adj seige overlay visual bug.ctr

•  Enter the Classical Era // 2. Build their Embelmatic Quarter // 3. Hover over the tile to check the tooltip
• Reproducibility: 5/5
• Expected Behavior: The tooltip should display localized text.
• Notes
• Attachments: Save, Screenshots, Logs etc...