@King Alpha,
Any AV with Game Mode will be good to try. The rest greatly depends on your computer setup and hardware. Windows Defender is not an issue at all (has Game Mode) when gaming. So, it would be the natural starting AV.
Here are some useful tips (
Does Antivirus Really Affect Your Gaming Performance?):
"Tips for Making Sure Your Antivirus Doesn’t Slow Your Gaming
We’ve looked at why your antivirus may affect your gaming experience. Now let’s sum up the key steps you can take to make sure this never happens.
- Choose an antivirus that doesn’t demand too many system resources. Keep in mind that free options target general users rather than gamers. When you install a free antivirus, you can expect essential protection and not much else.
- Look for an antivirus that features a gaming mode. With this mode on, you can boost your frames per second, reduce lag, and disable nagging notifications. If you game a lot, this feature is a big winner.
- Schedule automated scans when you’re not gaming. If your antivirus doesn’t let you do this, look for an alternative that gives you more control.
- Update your antivirus before you start gaming. Is your antivirus asking for updates too often? Reduce the number of updates to one a day.
- Don’t worry too much about Windows Defender. It won’t kill your gaming experience. Disable it only if you use a more advanced antivirus."
You can also look at the articles about optimizing gaming performance on Windows 10, for example:
How to Optimize Windows 10 for Gaming and Performance
https://www.ultimategamechair.com/optimize-windows-10-for-gaming/
Personally, I found out that on my computer the slowdowns are caused by updating Microsoft Store Apps. From the reasons I do not understand, the updates apply in the period of a few days. So, it is good to uninstall as much of them as you can.