Test via the In-Game Developer Console
To definitively check if the game is responding to speed commands, you can force it via the developer console: Press the ~ (tilde) key while in-game to open the console. Type the following command in lowercase: set_game_speed 3 (or set_game_speed 6 for an extreme test) and press Enter. If nothing changes visually, the game is being throttled at the driver or OS level.
Disable Vertical Sync (V-Sync) In-Game
This is the most common cause of this bug on high-end PCs. If you have a high-refresh-rate monitor (144 Hz, 240 Hz), the built-in frame limiter can break the simulation timers. Go to the game's graphics settings. Change the FPS limit from "Vertical Sync" to "No Limit". Alternatively, cap the frame rate manually at 60 FPS or 100 FPS. Many players on Reddit have confirmed that locking the game at 100 FPS instead of using V-Sync instantly "releases" the simulation speed.
Force Enable FreeSync / Enhanced Sync
Since you are running an AMD RX 7800XT graphics card, the Unity game engine might be handling frame buffering incorrectly. Open the AMD Software: Adrenalin Edition application. Navigate to the Gaming tab -> Captain of Industry. Enable AMD FreeSync (if supported by your monitor) or activate Radeon Enhanced Sync, while making sure V-Sync is turned off inside the game itself.
Change Display Mode
The game can sometimes glitch in standard windowed mode. In the graphics settings, switch to Borderless Fullscreen or pure Fullscreen. Try both options, as the game engine's behavior can differ significantly between them.
Verify Game Files and Clear Shader Cache
Sometimes, after game updates, the graphics cache causes hidden micro-throttling. In Steam, right-click on the game -> Properties -> Installed Files -> Verify integrity of game files. In your AMD Adrenalin driver settings, go to Settings (gear icon) -> Graphics -> scroll down to Advanced -> click Reset Shader Cache.