Minecraft telling me I don't have Internet connection (despite my internet is fine)

I regularly have problems with Minecraft Launcher. Some time ago it was rarer, now it happens more often. The appearing bug won’t let me open Minecraft in online mode, saying that Launcher couldn’t verify what products I own and the second one says that I don’t have proper Internet connection. I checked my Internet, it works perfectly fine. I can’t fix it by changing settings, turning on VPN or synchronizing date and hour (I saw somewhere that synchronizing helps, but not in this scenario). I always have to reinstall Launcher, but that also leads to another problem with installing it again. I download installer from official Minecraft site, click button to agree to terms connected with installing it and click button to install. Then some error occurs, telling me it wasnt installed successfully (0x800704C6). Again, fixing it is kinda random. I try VPN, synchronizing and try to force it by opening installer again and again. It works after few tries, but I find no rule to it (I didn’t change anything between trying but somehow once it works, once not). I am sure problem isnt caused by my Internet connection. As I said, it fixes somehow finally, but it’s really irritating when you want to chill after whole day and meet problem like that. It shouldn’t work that way.