Hi there for info are you using Reportico as standalone ( ie not within framework like joomla,Laravel etc) and which version?? Reportico 6?
There could be memory constraints
How long does it run before before terminating?
Perhaps, assuming you are in standalone mode, lets start by editing the file run.php and you will two lines :-
You could perhaps try increasing these values to give more time and more memory to the process?
Let me know if that helps