Needs your TV in the livingroom a different setting then the 1920x1080?
I don't know what you mean by "Needs your TV". The TV says it's running at 1920x1080. I don't think the resolution is the problem.
If not try the Clear type option (just type it in the seach bar)
Clear Type may be the solution. I forgot the name of it. I'll try that after I post this in case something gets really messed up.
the point of setting it back to 100% is just to test that the issue goes away... if that sorts it then yes its a Gpu problem and not say faultily monitor or some software glitch
I set it back to 100%, which of course made text so small it's very difficult to read, then set it back to 125%, and the blurriness seems to be less now... woohoo! It's actually maybe halfway between normal clearness and the blurriness it was before. So maybe this will be tolerable now. I had to squint at times before. I still notice my eyes have to adjust focus a bit, but that's much better.
getting a Gpu card instead of the inbuild chip would prob sort it but the issue is weather your computer can actually take a Gpu card i.e, does it have a slot to put the card into and we need to know your motherboard model or just the laptop model in order to know that before you spend extra cash on a Gpu card you can't use
My guess is a separate GPU card would fix the issue, but I've seen on other computers where one caused the issue

and another made it worse. So that's a gamble, and I'd have to research which card to get anyway that would work with my power supply and that I could use for something else as well such as gaming. That's a whole other rabbit hole, but I'll be glad to visit any links you recommend for finding compatible ones based on computer.
i assume he has a monitor and not a TV but yes bochane setting to a lower rez on a larger screen is in effect the same as having 125% but i'd still test the issue goes away at 100% as a first step
It's a normal TV with an HDMI input (though not a smart TV) running through the "PC" type of input (this is set in TV input settings by the way, where any other setting looked horrible or didn't work at all).
I've tried setting the Windows output to less than Full HD, and either everything looked worse, or the borders were not right, or it was stretched etc... and I don't care to go further down that troubleshooting rabbit hole, as Full HD just works regardless of some blurry window text.