This is the first thing I would “solve” as old versions are not supported. And I honestly dont know the exact behaviour of this version anymore.
Would be better to update to the newest Version (you can find them here → GitHub pls use 1.5.9)
Well pls check the Chrome Dev-Console (Tab Network) it shows you if it get loaded or if a cached version is getting delivered.
This is related to another problem, which is again related to CodeIgniter (see HERE)
I do not have this issue, but if you are curious about if it is related to Chrome or not, just try to reproduce the issue in FireFox/Edge/Opera etc.