Thank you for sharing your findings. If the problem was the data within the database, then the issue would be present in both servers. Therefore, I don’t think url_rewrite is related.
Editing MySQL Variables via PhpMyAdmin
If you log in phpMyAdmin as root, you will see a tab in the upper-right of the screen:
This shows you all of the MySQL Variables that you can set, which can also be edited from here.
1. Compare MySQL Variables
I would compare the variables of the 2 servers to see if you can identify a “dodgy” variable on your main server that is having an adverse effect.
2. Tweak MySQL Variables
Personally, I find the default MySQL Variables a little low. And this has caused me issues with larger sites in the past because I forgot to tweak them. Try amending the following MySQL Variables for improved performance:
innodb-log-file-size=100Minnodb-buffer-pool-size=2Ginnodb-log-file-size=250M
Making MySQL Variable changes permanent
For the most part, any changes you make will likely be overwritten next time the mysql service is restarted. So, in order to make sure any MySQL Variable changes are permanent you will have to edit the MySQL Configuration file. This requires root or superuser privileges. The location of the file will vary depending on both your Web Host, SQL Version and OS - So, you’ll have to find this yourself.
If you setup your Web Server using my tutorial then there is a good chance that you’ll find the file in one of these 2 locations:
/etc/mysql/mysql.conf.d/mysqld.cnf- or
/etc/mysql/my.cnf
Simply replace the Variable that you want to change. If it doesn’t exist, then it will assign a default value - In this scenario just create a new line in the file. Once you’ve edited and saved the file, restart mysql to apply the changes.
There is no “undo” button. Always backup or take a note of any variables you Add/Edit/Remove.