Codeigniter 4 development mode returning extra HTML

Hi to everyone,
I'm having an issue with Codeigniter 4 in development mode.
It is now the second case that, when I send data via Ajax, the code breaks in development mode since, aside from the JSON string I need, I also get some code from the debugger like the one below:

<script type="text/javascript"  id="debugbar_loader" data-time="1604332610" src="http://localhost/index.php?debugbar"></script><script type="text/javascript"  id="debugbar_dynamic_script"></script><style type="text/css"  id="debugbar_dynamic_style"></style>

To make sure everything runs smoothly I always need to switch back to production mode.
Anyone knows how to solve this problem? Thanks