Matomo 4.5.0 does not work with opcache (php-fpm 7.4.15)

Hello all.

Recently we have upgraded our matomo to 4.5.0 version and since then we were unable to access it via browser. Processing via console was working without any issue, generate and send reports, etc, but unable to access it other way than via console.

We have deactivated all plugin - directly editing config.ini.php - try unlimited memory configuration in php.ini but no success: everytime we try to access matomo via browser it show a 503 error.

We were unable to get more information on this has no error in php or webserver (apache) logs where logged.

The only thing that we haven’t try yet was deactivate opcache directly in php configuration and… voilá it start to work again has nothing has happened before!

In all previous versions of matomo we have opcache enabled and no problem at all, this is the first one that origins such a bug.

Some system info:

PHP version >= 7.2.5 7.4.15
Matomo Version 4.5.0
Matomo Update History 4.4.1,4.3.1,4.2.1,4.1.1,3.14.0
PHP_OS Linux
PHP_BINARY /php74/sbin/php-fpm
PHP SAPI fpm-fcgi

All system validation in matomo gui is green / passed.

Has said this is a weird bug has no information is logged in php or apache logs nor in any system logs or journal info.

Thanks, Pedro Estevão