The connection was reset

The connection was reset

The connection to the server was reset while the page was loading.

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Not sure what cause this issue, each time I do changes to the WordPress dashboard, the site keeps on showing the error above see attach screencast: https://screencast.com/t/XrAbaO8ptbS

I have done deactivating all the plugin and activate only one plugin and apply changes still it keeps on showing the connection was reset.

I tried also changing themes of the site, still showing same error.

I tried increasing php memory limit, htaccess, wp-config still nothing.

I cannot update the wordpress version via automatically because each time I request the automatic update the connection keeps resetting.

I cannot also do a manual update for the wordpress the site block me from uploading files

Any insights for this one?