Weird problem - steam games are showing 5-6 fps

[New Player]

Hi, I have Acer Predator Helios 300 laptop with 9th Gen i7 & 1660ti. It can handle most of the games, even demanding games can be played in 50-60 fps in medium settings & no stuttering - at least it used to.
I got Warhammer End Times: Vermintide from a giveaway, and I was playing that last month quite smoothly, no issue. After 5-6 hours into the game, I was tinkering with NVIDIA GeForce Experience (v461.**) settings, and I thought to click on "Optimise". After that I logged off (didn't check the game), and didn't play any game for a week afterwards. On 2nd Jan, when I opened that game again, I saw I was barely getting 5-6 fps with horrible stuttering. Thinking that it is in game issue, I opened Bioshock 2 (steam), I saw same issue with 3-5 fps. I thought that my hardware got damaged, so I ran some benchmarks. In Geekbench, single, multi core and OpenCL scores were 1100, 5326 & 67646. On 3DMark (Steam) "Time Spy" showed 5931 (great), with CPU & GPU scores were 6571 & 5831 with no crash - clearly not a hardware issue. Then I updated the game ready driver to latest 497.29 & clean installed it, but that didn't solve. Disabled NVIDIA drivers from device manager - then I found even in integrated graphics, it is producing same 3-5 fps. Disabling integrated graphics driver didn't improve it either. I checked task manager, games were using dedicated GPU. CPU & GPU temperatures were within safe limit, and usages of CPU, GPU, RAM & VRAM were good as well.
Then I saw something even weirder. Installed & fired up Blair Witch and Second Extinction from Epic Games - there were no issue. I launched Iratus from GOG, no stuttering either. So, this is only happening to steam games, regardless of the hardware or drivers. Things I also checked:
1) Storage issue: Moved the games to my SSD, where my GOG games were - no improvement.
2) NVIDIA settings: Reset the power usage to optimal performance, set PhysX engine to GPU, set resolution to the native resolution (1080p 144Hz), and in GeForce experience, set to not optimise new games.
I also googled a lot for past 2 days, followed a lot of forum pages - but found no solution. I can't play any game from my steam library - can you please help? I don't have an unlimited internet, so uninstalling everything and reinstalling steam is not an option for me. Thanks.

[Cathulhu]

Do a clean install of your videodriver and never ever touch the optimize button again.

[Gerardo El Magias]

u tried disabling the steam overlay ingame? no idea if it will work but who knows

[crunchyfrog]

Cathulhu's right here. First port of call - reinstall drivers.

And optimize buttons, just NO!

This may be more of a long shot but I'll mention it because I've seen it before. Even if it says it's using the correct graphics card, I have seen Windows updates ruin this and default to the INtel integrated chipset instead. YOu could force things just to check by going to your NVidia utiltity and setting up the games to use the right card with the correct settings. They tend to brute force things.

[New Player]

Disabling steam overlay didn't help. And I also clean installed the driver - didn't help either. I won't touch optimize, never again - but how do I get out of this mess now?

[New Player]

Originally posted by crunchyfrog:

Cathulhu's right here. First port of call - reinstall drivers.

And optimize buttons, just NO!

This may be more of a long shot but I'll mention it because I've seen it before. Even if it says it's using the correct graphics card, I have seen Windows updates ruin this and default to the INtel integrated chipset instead. YOu could force things just to check by going to your NVidia utiltity and setting up the games to use the right card with the correct settings. They tend to brute force things.

I tried forcing from Nvidia control panel, as well as by disabling the integrated graphics driver from device manager. Didn't help.

[crunchyfrog]

Originally posted by New Player:

Originally posted by crunchyfrog:

Cathulhu's right here. First port of call - reinstall drivers.

And optimize buttons, just NO!

This may be more of a long shot but I'll mention it because I've seen it before. Even if it says it's using the correct graphics card, I have seen Windows updates ruin this and default to the INtel integrated chipset instead. YOu could force things just to check by going to your NVidia utiltity and setting up the games to use the right card with the correct settings. They tend to brute force things.

I tried forcing from Nvidia control panel, as well as by disabling the integrated graphics driver from device manager. Didn't help.

Ah ♥♥♥♥, I was hoping that might overrrule it.

The only other long shot I can offer is to check if something else untoward is interfereing with it on your PC.

Try botting is Safe Mode with Networking. JUst run Steam and start a game, see how it bears out. It MAY look crap and choose a weird resolution but see how you get on and can replicate the issue.

If you cannot, then safe to say it's going to be some software running on your PC that is causing this, and then it's down to process of elimination to fouind out what background thing it is.