Are they internet games like on Steam? Try this. Go into your game and set the game to 'default' settings or find the 'reset game' button. Make sure you write down your game settings as this will erase all your game settings.
Steam like to remember things about you and games. Your game settings are reinstalled if you uninstall and reinstall games. Sometimes the game will remember a 'crash' and reprogram it like a game setting.. . yeah, back into the game. It's weird but it a good thing since Steam looks after your game purchases, settings and preferences, reminds you what's on sale and announces upcoming games you like. Just every once in a while it remembers the wrong thing.
Oh yes, it could be your PSU.
Chieftech isn't a brand I've heard of till just now. Excluding your PSU, it's other family members are on a Lemon list.
http/www.johnnylucky.org/power-supplies/psu-lemon-list.html
And the same brand under a different name (Powmax) has it 'avoid immediately' a few years back on Tom's Hardware. Just letting you know.
http/www.tomshardware.com/forum/id-2547993/psu-tier-list.html
Here are a few more 'good' PSU listing from around the neighborhood.
http/www.johnnylucky.org/power-supplies/psu-recommendations.html
https
/linustechtips.com/main/topic/631048-psu-tier-list-updated/
I fried up 3 computers using bad PSUs. Ultra, cheapest Antec 500w and the first year Corsair RM750 by Chicony.
If it's doing fine, use it till you can afford a new one but I'd seriously consider replacing it.
Hope this helps.