And when you manually click the button to "Check for updates" you are not offered anything more current??
IF it were me I would backup all my critical data including using something like
https://www.macrium.com/reflectfree?x-ca=blog
To create a full disk image of all existing partitions.
THEN....
I would go here
https://www.microsoft.com/en-us/software-download/windows10
And use the Media Creation Tool to get the latest ISO available
And use that to perform an in-place upgrade by double clicking the ISO (once you have it saved to your computer) to mount it and then running Setup.exe from within your current install.
You are running a full version behind.
NOTE: If you are running any third party security software uninstall it before upgrading
AND
Disconnect any USB connected peripherals leaving only a USB connect mouse, a USB connected keyboard and the monitor.
No addon wireless dongles of any type.
That may very well fix your current issue and if it doesn't, at least we know that we're all on the same page comparing apples to apples.