Mautic API Authentication problem

Your software
My Mautic version is: v4.4.11
My PHP version is: 7.4.33
My Database type and version is: Percona Ver 8.0.33-25

Your problem
My problem is:
I have a strange problem. I am trying to connect to the API, and connecting with an n8n on the same server works perfectly fine. I try to connect from an n8n at another location and I cannot connect. Trying with OAuth 2, after logging on and confirming that I want to connect I get an Error: connect ETIMEDOUT, with the IP of the Mautic server. Trying to connect with credentials just times out. I tried to connect with a WordPress plugin and the same problem. No way to connect.

These errors are showing in the log:
I believe they are unrelated, because it happened all before my attempts:
[2024-05-01 09:00:48] mautic.WARNING: PHP Warning - require(/var/www/html/var/cache/prod/Container5IRGbkK/getMautic_Form_Type_FormconfigService.php): failed to open stream: No such file or directory - in file /var/www/html/var/cache/prod/Container5IRGbkK/appAppKernelProdContainer.php - at line 2338 {“file”:“getMautic_Form_Type_FormconfigService.php”,“lazyLoad”:true} {“hostname”:“603ae2c7cf02”,“pid”:3925531}
[2024-05-01 09:00:48] mautic.ERROR: PHP Notice: require(): Failed opening required ‘/var/www/html/var/cache/prod/Container5IRGbkK/getMautic_Form_Type_FormconfigService.php’ (include_path=‘.:/usr/local/lib/php’) - in file /var/www/html/var/cache/prod/Container5IRGbkK/appAppKernelProdContainer.php - at line 2338 {“hostname”:“603ae2c7cf02”,“pid”:3925531}
[2024-05-01 09:00:48] mautic.ERROR: Symfony\Component\Debug\Exception\FatalErrorException: Notice: require(): Failed opening required ‘/var/www/html/var/cache/prod/Container5IRGbkK/getMautic_Form_Type_FormconfigService.php’ (include_path=‘.:/usr/local/lib/php’) - in file /var/www/html/var/cache/prod/Container5IRGbkK/appAppKernelProdContainer.php - at line 2338 {“hostname”:“603ae2c7cf02”,“pid”:3925531}
[2024-05-01 09:00:48] mautic.WARNING: PHP Warning - require(/var/www/html/var/cache/prod/Container5IRGbkK/getSecurity_Firewall_Map_Context_MainService.php): failed to open stream: No such file or directory - in file /var/www/html/var/cache/prod/Container5IRGbkK/appAppKernelProdContainer.php - at line 2338 {“file”:“getSecurity_Firewall_Map_Context_MainService.php”,“lazyLoad”:true} {“hostname”:“603ae2c7cf02”,“pid”:3937634}
[2024-05-01 09:00:48] mautic.ERROR: PHP Notice: require(): Failed opening required ‘/var/www/html/var/cache/prod/Container5IRGbkK/getSecurity_Firewall_Map_Context_MainService.php’ (include_path=‘.:/usr/local/lib/php’) - in file /var/www/html/var/cache/prod/Container5IRGbkK/appAppKernelProdContainer.php - at line 2338 {“hostname”:“603ae2c7cf02”,“pid”:3937634}
[2024-05-01 09:00:48] mautic.ERROR: Symfony\Component\Debug\Exception\FatalErrorException: Notice: require(): Failed opening required ‘/var/www/html/var/cache/prod/Container5IRGbkK/getSecurity_Firewall_Map_Context_MainService.php’ (include_path=‘.:/usr/local/lib/php’) - in file /var/www/html/var/cache/prod/Container5IRGbkK/appAppKernelProdContainer.php - at line 2338 {“hostname”:“603ae2c7cf02”,“pid”:3937634}
[2024-05-01 09:00:48] mautic.WARNING: PHP Warning - require(/var/www/html/var/cache/prod/Container5IRGbkK/getSecurity_Firewall_Map_Context_MainService.php): failed to open stream: No such file or directory - in file /var/www/html/var/cache/prod/Container5IRGbkK/appAppKernelProdContainer.php - at line 2338 {“file”:“getSecurity_Firewall_Map_Context_MainService.php”,“lazyLoad”:true} {“hostname”:“603ae2c7cf02”,“pid”:3945474}
[2024-05-01 09:00:48] mautic.ERROR: PHP Notice: require(): Failed opening required ‘/var/www/html/var/cache/prod/Container5IRGbkK/getSecurity_Firewall_Map_Context_MainService.php’ (include_path=‘.:/usr/local/lib/php’) - in file /var/www/html/var/cache/prod/Container5IRGbkK/appAppKernelProdContainer.php - at line 2338 {“hostname”:“603ae2c7cf02”,“pid”:3945474}
[2024-05-01 09:00:48] mautic.NOTICE: PHP Notice - Undefined variable: inline - in file /var/www/html/offline.php - at line 77 {“inTemplate”:false,“isAjax”:false,“message”:“The site is currently offline due to encountering an error. If the problem persists, please contact the system administrator.”,“submessage”:“System administrators, check server logs for errors.”,“inDev”:false,“base”:“/”,“root”:“/var/www/html”,“assetPrefix”:“”,“paths”:{“themes”:“themes”,“assets”:“media”,“asset_prefix”:“”,“plugins”:“plugins”,“translations”:“translations”,“local_config”:“%kernel.root_dir%/config/local.php”,“root”:“/var/www/”,“app”:“app”,“bundles”:“app/bundles”,“vendor”:“vendor”},“assetBase”:“/media”} {“hostname”:“603ae2c7cf02”,“pid”:3945474}
[2024-05-01 09:00:48] mautic.ERROR: Symfony\Component\Debug\Exception\FatalErrorException: Notice: require(): Failed opening required ‘/var/www/html/var/cache/prod/Container5IRGbkK/getSecurity_Firewall_Map_Context_MainService.php’ (include_path=‘.:/usr/local/lib/php’) - in file /var/www/html/var/cache/prod/Container5IRGbkK/appAppKernelProdContainer.php - at line 2338 {“hostname”:“603ae2c7cf02”,“pid”:3945474}

Steps I have tried to fix the problem:
clearing the cache