Issue with obtaining assets in Perch console

I was recently attempting to create a subdomain in order to serve images, and I don't know if that has affected the site but it seems that a query string, i.e. ?v=2.8.34 is being appended after filenames so:

https://example.com/perch/core/assets/css/login.css becomes https://example.com/perch/core/assets/css/login.css?v2.8.34

The assets in question are accessible without query string so is this normal or has something I have done corrupted the installation?

I tried resetting folder permissions on the site but to no avail.

I'm confident that I'd be able to restore the website, e.g. from a CPanel backup or manual install and creating a new database but I'd rather not do this if possible.

I have seen this before but have been able to rectify it but as of now I am at a standstill.