PHP fatal error, compatibility PHP7.4?

There’s a PHP fatal error on the ‘edit page’ screen where I expect a dropdown to show me a list of pages the popup can be shown on. The scenario looks to me like a PHP compatibility issue. Has the plugin been tested on PHP7.4?

I am working with:
Nginx
PHP7.4
Wordpress 5.8.2
WooCommerce 5.9.0
Splash Popup for WooCommerce (BeRocket): 3.5.7.2

Here’s a stack-trace:
`2021-12-09T12:56:50+00:00 CRITICAL Uncaught TypeError: Cannot access offset of type string on string in /home/…./public/wp-content/plugins/splash-popup-for-woocommerce/templates/pages.php:33
Stack trace:
#0 /home/…./public/wp-includes/template.php(772): require()
#1 /home/…./public/wp-content/plugins/splash-popup-for-woocommerce/berocket/framework.php(935): load_template()
#2 /home/…./public/wp-content/plugins/splash-popup-for-woocommerce/addons/deprecated_old_popup/popup.php(72): BeRocket_Framework->br_get_template_part()
#3 /home/…./public/wp-admin/includes/template.php(1395): BeRocket_splash_popup_deprecated->meta_box_settings()
#4 /home/…./public/wp-admin/edit-form-advanced.php(688): do_meta_boxes()
#5 /home/…./public/wp-admin/post.php(206): require(‘…’)
#6 {main}
thrown in /home/…./public/wp-content/plugins/splash-popup-for-woocommerce/templates/pages.php op de lijn 33`

Here’s a screenshot that should give you an idea of what I’m seeing:
https://phitech.consulting/wooc_splash_popup_error.jpg

Please let me know what else you need for further debugging.