TurboBoost failure playing games on AC power

CPU clock speed drops to sub 1.7Ghz when a game is running in the foreground and the laptop is on AC power. Leave the game in the foreground, unplug from AC using batter, and it appears TurboBoost enables and the PC runs just below 2.4Ghz. The same issue occurs when minimizing the game while plugged in to AC power. Remove AC power and clock speed remains just below 2.4Ghz. I have installed all available windows updates, re-installed updated chipset drivers from acers website.

Screen 1: Game in foreground, AC power, lowered clock

Screen 2: Game in foreground, battery power, appears TurboBoost is enabled

Screen 3: Game minimized (still running), AC power, appears TurboBoost is enabled

Screen 4: Game minimized (still running), batter power, appears TurboBoost is enabled

I have an Acer Aspire R3-471T laptop

Intel Core i5 4210U 1.7Ghz (2.4Ghz)

Windows 10 Pro Technical Preview Build 9926 (I am aware running an unfinished version of windows could be the issue)

The issue was still present prior to updating to the most recent build. It also occurs regardless of game, it even occurs with emulators. Am I missing something here?

Thanks in advance!