layout – Viewport scaling, discrepancies between design and result

Context of this problem will be probably best seen when I design web apps. When mocking up design, there is huge discrepancy between x px in browser, in Figma and measure in Photoshop.Scaling problem

Here is printscreen of Figma, PS and WebBrowser windows. They are same viewport zoom, they are displayed on same monitor. As you see Figma says block is 300px but PS measures around 340px. Even bigger difference is between coded block that is supposed to be relevant atleast to one of the measurements, but even just optically width is just radically off. Result of measurement in PS of browser screen is ~370px.

I understand that there is settings in Win10 that adjusts scaling of apps to default 125% because pixels today have much higher DPI which messes up some designs with fine lines and smaller details but …

I havent seen difference between feature turned off and on
It does not explain difference between 3 applications + XD which I left for same exact reason bit back

here is link to topic where I have tried to resolve problem with good people of reddit.