Whenever there is a new update available for WordPress itself, it is NOT recommend to immediately upgrade your site the moment the update has become available. That is particular true whenever WordPress is releasing an update that includes a major version change; for example. v4.4x to v4.5.x. The reason being that those type of updates usually include major changes to important core features, that can easily break your overall website, if any of your active plugins or your theme is not yet adjusted for that change.
Please give every developer a little time to properly test their product with a new WordPress version and if required, release updates for a plugin/theme in order to be compatible with the new WordPress release. A good rule of thumb would be to wait about a week after a new WordPress release has been published, before actually updating your site. That will give plugin and theme developers sufficient time to publish any required updates for their products.
If any of your plugins or theme have been purchased on Envato, it will also take a little time, until those updates will be available to you on Envato. Whenever an author is uploading an update to Envato, it will undergo an approval process by Envato that can NOT be controlled by the author. And whenever there are major changes to WordPress itself, Envato will often times receive many update approval requests at once, which will cause a delay in overall approvals. If your theme or plugin allows for an auto-update procedure via WordPress itself (usually requires you to register your license key), you can in most cases get the update before it has been approved by Envato.
Also, before each WordPress update, you should make at least a backup of your WordPress database, as many WordPress updates will make changes to the underlying database and its structure, and there is always a chance of things going wrong. If at all possible, make a full system backup (database + all files), so you can easily revert back in case there are (still) any incompatibilities between the new WordPress version and any of your plugins or theme.
After you successfully updated WordPress itself, and any plugins or themes that also required an update, you should also always empty your browser cache and any caching plugins you might be using, in order to ensure, that you are actually using the newest file versions, when it comes to JS and CSS files. If your system is loading files via CDN networks, ensure that all those connections have been updated as well.