Usually, when an update comes out, I always wait at least a week or 2 before updating the theme. (in case something goes wrong and you release a patch some days later) – yes, you are right.
Please download the theme (8.1.5v) and Core (4.1.5) – https://dropmefiles.com.ua/en/aUZyvf4A and install them on your site, check if the problem persists. Let us know the result
Do not forget to create a full backup before the update.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.