php error when upgrading from 7.3 to 8.0

Hello,
we encounter php errors with this plugin when switching from php 7.3 to 8.0.

Uncaught TypeError: Cannot access offset of type string on string in /var/customers/webs/XXXXX/wp-content/plugins/yikes-inc-easy-custom-woocommerce-product-tabs/admin/class.yikes-woo-generate-html.php:215

Stack trace:

#0 /var/customers/webs/XXXXX/wp-content/plugins/yikes-inc-easy-custom-woocommerce-product-tabs/admin/class.yikes-woo-generate-html.php(112): Yikes_Woo_Custom_Product_Tabs_HTML->display_woocommerce_wp_text_input()

#1 /var/customers/webs/XXXXX/wp-content/plugins/yikes-inc-easy-custom-woocommerce-product-tabs/admin/class.yikes-woo-generate-html.php(40): Yikes_Woo_Custom_Product_Tabs_HTML->generate_tab_html()

#2 /var/customers/webs/XXXXX/wp-content/plugins/yikes-inc-easy-custom-woocommerce-product-tabs/admin/class.yikes-woo-tabs.php(102): Yikes_Woo_Custom_Product_Tabs_HTML->generate_html()

#3 /var/customers/webs/XXXXX/wp-includes/class-wp-hook.php(292): YIKES_Custom_Product_Tabs_Custom_Tabs->product_page_yikes_custom_tabs_panel()

#4 /var/customers/webs/XXXXX/wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters()

#5 /var/customers/webs/XXXXX/wp-includes/plugin.php(484): WP_Hook->do_action()

#6 /var/customers/webs/XXXXX/wp-content/plugins/woocommerce/includes/admin/meta-boxes/views/html-product-data-panel.php(53): do_action()

#7 /var/customers/webs/XXXXX/wp-content/plugins/woocommerce/includes/admin/meta-boxes/class-wc-meta-box-product-data.php(33): include('...')

#8 /var/customers/webs/XXXXX/wp-admin/includes/template.php(1389): WC_Meta_Box_Product_Data::output()

#9 /var/customers/webs/XXXXX/wp-admin/edit-form-advanced.php(688): do_meta_boxes()

#10 /var/customers/webs/XXXXX/wp-admin/post.php(206): require('...')

#11 {main}

thrown

Do you have any information regarding this?
If we downgrade the php version back to 7.3, it is fine, but the site loses performance. Any ideas?