Problems after upgrade from PHP 7.4 to PHP 8.0 on Red Hat

I’m running Matomo version: 4.14.1, with 10.3.35-MariaDB and PHP version: 8.0.28 on Apache.
Today I updated our host to PHP 8.0 from PHP 7.4.
Matomo has been running smoothly for the past year and a half.
After the update I encountered the following problems:

  1. all data and graphs are visible until end of March. In my Dashboard in April I see “Sequence ‘matomo_archive_numeric_2023_04’ not found.” in box “Visits over time” and "Oops… there was a problem during the request. " in all others widgets
  2. Table matomo_sequence is creating multiple “matomo_archive_numeric_2023_04” rows (10 or more)
  3. System Check reports no error except for Warnings with failed curl_exec. Unable to execute check for $MATOMO_URLconfig/config.ini.php: curl_exec: Connection timed out after 2001 milliseconds.
  4. It’s impossible to follow links to upgrade Matomo and plugins. All returns generic security errors.

What do I need to check?