cannot read javascript though it is loaded

I have a view with codeigniter 4.4.8 but i cant link a javascript with   
<script src="=<?= base_url('assets/js/messages.js') ?>" type="text/javascript" >
</script>
The script does appear when i paste the absolute url in the browser though, and it appears on the network tab in developer tools, but i cant debug it by clicking on debugger view option with right mouse click. The https response is 200 ok so it is loaded, but codeigniter does not "see it". When i paste it in the view, not link it , it all works fine.

What could be the issue? I am going a bit insane hahha

I don't understand what you say exactly, but is the return value of base_url('assets/js/messages.js') correct?

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