Frequent rebuild warning

I'm frequently getting the message about rebuilding permissions tables

The content access permissions need to be rebuilt.

The UI hangs/fails attempting to rebuild on the page that says "Rebuilding content access permissions" it has a bar and stays at "Completed 0 of 1" then gets a 500 error. I'm guessing timeout?

An AJAX HTTP error occurred.
HTTP Result Code: 500
Debugging information follows.
Path: /batch?id=18611&op=do_nojs&op=do
StatusText: Internal Server Error
ResponseText: The website encountered an unexpected error. Please try again later.

So, using Drush it finishes successfully.

$ lando drush php-eval 'node_access_rebuild($batch_mode = TRUE);' -v
Include /var/www/.drush/pantheon/drush8                                                                                                                                                                                                                 [notice]
Executing: mysql --defaults-extra-file=/tmp/drush_C5J9DL --database=pantheon --host=database --port=3306 --silent  < /tmp/drush_5fsQtv
Executing: mysql --defaults-extra-file=/tmp/drush_4wMS1h --database=pantheon --host=database --port=3306 --silent  < /tmp/drush_fL8ZP1
Loading outputformat engine.                                                                                                                                                                                                                            [notice]
Command dispatch complete                                                                                                                                                                                                                               [notice]

It works for maybe one page load and then the warning comes back. Reloading the same page it goes away but going to another page it shows back up sometimes.

I don't see any other issues like this. Am I doing something wrong?