make some changes to the content.
the server detects the change, rebuilds, and reload the browser too but updated content does not show up.
using version
hugo v0.81.0-59D15C97+extended linux/amd64 BuildDate=2021-02-19T17:07:12Z VendorInfo=gohugoio
tried with v0.80 also
I tried following this command
hugo server --disableFastRender --renderToDisk --noHTTPCache --ignoreCache but does not work
The question is how you call your server 
If you don’t use the parameter --disableFastRender for hugo server then Hugo will only render changes it detects, not ALL of them. Try to see if hugo server --disableFastRender solves your problem.
You need to STOP your hugo server and restart it before it shows different results.
Other than this, often publish dates after NOW() will not result in changes.
Post a link to a public repo if nothing of that works.