In this case, you may wait for theme update.
Or try one more time to fix the problem. I’ve sent portfolio.php file to your email. Please rename your current portfolio.php and upload new one, then select Permalinks > Common Settings > Post name and check the problem https://www.criticalenvironmentsolutions.co.uk/brand/berkshire/.
In case the problem will be fixed, you may delete the old portfolio.php file, if it won’t help – delete new file and rename the file back. Let me know result.
