PHP8: PDF and Excel failed

Hey,

the PDF and Excel Export failed in PHP8.

Here are the logs:

[05-Apr-2021 16:18:41] WARNING: [pool www] child 18 said into stderr: "NOTICE: PHP message: PHP Warning:  "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in /usr/share/webapps/wordpress/wp-content/plugins/advanced-cf7-db/admin/pdfgenerate/dompdf/src/Dompdf.php on line 610"
[05-Apr-2021 16:18:41] WARNING: [pool www] child 18 said into stderr: "NOTICE: PHP message: PHP Warning:  "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in /usr/share/webapps/wordpress/wp-content/plugins/advanced-cf7-db/admin/pdfgenerate/dompdf/src/Dompdf.php on line 631"
[05-Apr-2021 16:18:41] WARNING: [pool www] child 18 said into stderr: "NOTICE: PHP message: PHP Warning:  "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in /usr/share/webapps/wordpress/wp-content/plugins/advanced-cf7-db/admin/pdfgenerate/dompdf/lib/Cpdf.php on line 467"
[05-Apr-2021 16:18:41] WARNING: [pool www] child 18 said into stderr: "NOTICE: PHP message: PHP Warning:  "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in /usr/share/webapps/wordpress/wp-content/plugins/advanced-cf7-db/admin/pdfgenerate/dompdf/lib/Cpdf.php on line 474"
[05-Apr-2021 16:18:41] WARNING: [pool www] child 18 said into stderr: "NOTICE: PHP message: PHP Warning:  "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in /usr/share/webapps/wordpress/wp-content/plugins/advanced-cf7-db/admin/pdfgenerate/dompdf/lib/Cpdf.php on line 481"
[05-Apr-2021 16:18:41] WARNING: [pool www] child 18 said into stderr: "NOTICE: PHP message: PHP Warning:  "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in /usr/share/webapps/wordpress/wp-content/plugins/advanced-cf7-db/admin/pdfgenerate/dompdf/lib/Cpdf.php on line 488"
[05-Apr-2021 16:18:41] WARNING: [pool www] child 18 said into stderr: "NOTICE: PHP message: PHP Warning:  "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in /usr/share/webapps/wordpress/wp-content/plugins/advanced-cf7-db/admin/pdfgenerate/dompdf/src/Css/Stylesheet.php on line 1360"
[05-Apr-2021 16:18:41] WARNING: [pool www] child 18 said into stderr: "NOTICE: PHP message: PHP Warning:  "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in /usr/share/webapps/wordpress/wp-content/plugins/advanced-cf7-db/admin/pdfgenerate/dompdf/src/Renderer/Text.php on line 140"
[05-Apr-2021 16:18:50] WARNING: [pool www] child 16 said into stderr: "NOTICE: PHP message: PHP Fatal error:  Array and string offset access syntax with curly braces is no longer supported in /usr/share/webapps/wordpress/wp-content/plugins/advanced-cf7-db/admin/class/PHPExcel/Shared/String.php on line 529"
[05-Apr-2021 16:18:50] WARNING: [pool www] child 16 said into stderr: "sh: line 1: /usr/bin/sendmail: No such file or directory"