We have checked it on PHP 7.4 and its working fine without any issue.
Can you please deactivate the plugin one by one and check? It may be some issue from some plugin too.
Just login to our site with the same username while you have purchase before and you will be redirected to your account page where you can see your order detail with download tab button to get latest version of the theme, download the file and upload to your WP theme directory and activate it.
May your subscription have already expired.
If so please renew your pending subscription order which you can see on your order tab from your account page.