Hello Andrei,
Thanks for writing to us.
There might be a few different reasons for this issue, I would suggest you troubleshoot with a few of the common issues before we investigate your settings.
- Testing for Plugin Conflict
- CSS/JS Customization
- Version Compatibility
- Disabling Cache
- Permalink
I recommend the following troubleshooting.
1.) Increase PHP Memory Limit
2.) Increase PHP Execution Time Limit
I recommend increasing the following server settings to the specified value or larger. Please consult to your web host for all these server settings
PHP configuration recommended
memory_limit = 512M
upload_max_filesize = 512M
post_max_size = 512M
max_execution_time = 300
max_input_time = 300
If none of those work, It would be best if you could copying your live website to your staging area. and send your details in a secure note so that we can investigate your setting without breaking your live site. Please provide the following details
- WordPress Login URL
- Admin level username and password
You can find the Secure Note button at the bottom of your posts
Thanks