Large amount of leads are not displayed in Reports module

Using SuiteCRM 7.8.2 - Unable to view the reports for large number of leads. Works fine for smaller volumes, but not for 1000 and above. For all the modules, facing the same error.
“An error has occured : There was an error processing your request, please try again at a later time.”

I increased the post_max_size to 60MB,
upload_max_filesize to 60MB,
max_input_time to 60,
memory_limit to 256MB
Then restarted the Webserver. But, facing the same error.

SuiteCRM Version used: 7.8.2
Environment name and version (e.g. MySQL, PHP 7):
Operating System and version (e.g Ubuntu 16.04): Ubuntu 16.04
Theme: Suite7

Any solutions please. Thanks.

If you can give it an even higher memory_limit (like 512), please try that.

If not, or if it doesn’t work, check your logs for any error messages.