PHP8.1 CI3 deprecated errors

I'm looking to migrate from PHP7.4 to PHP 8.1 and I get errors like:
PHP Error was encountered
Severity: 8192
Message: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated
Filename: libraries/Javascript.php
Line Number: 658

Line Number Trace:
            $str = $this->_open_script($external_file);
        }
        elseif (strpos($this->_javascript_location, 'http://') !== FALSE)
        {
            $str = $this->_open_script($this->_javascript_location.$external_file);

I thought CI3 can support PHP 8? Has anyone ran into these same issues?



        }

Are you running CodeIgniter 3.1.13?

akeni : I run CI 3.1.13 with PHP8.1 and is all running fine (I had to do some fixes in my app code - but framework code is fine)