How to reproduce:

• Click on Antarctic
• New Base
• Hideout (displays: “Maintenance: 9 CPU, 2100 money”)
• OK
• Wait for finish building
• Open your new hideout base
• Check the displayed maintenance

For me, the base displays 0 CPU, 2100 money maintenance cost.
This is inconsistent, the game can't decide how many CPU are needed for maintenance (9 vs 0).