Read time value of node in view
You need a patch that hasn't been merged yet. 

Issue is here - https://www.drupal.org/project/read_time/issues/2819071

The patch was created here -  https://www.drupal.org/project/read_time/issues/2819071#comment-13416093
You need anther module, so read that ^

In case you haven't applied a patch before, here's the link to the documentation on drupal.org about it. https://www.drupal.org/patch/apply

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Another option, change your view from Fields to Content. Add a view mode to your content type if you need to with only the fields you need.