Mautic REST-API returns 500 since update to 5.2.1

[imog]

My Mautic version is: 5.2.1
My PHP version is: 8.1.31
My Database type and version is: 8.0.40 MySQL

Regardless of which endpoint i connect to, i get this in return:

curl http://apiuser:apipassword@localhost/api/contacts
{
    "errors": [
        {
            "message": "Looks like I encountered an error (error #500). If I do it again, please report me to the system administrator!",
            "code": 500,
            "type": null
        }
    ]
}

I do not get any error logged for this in Mautic logs.

[imog]

My server was extremely busy (100% CPU). After cleaning this problem, the API started working again.
Is there some kind of protection internaly that returns 500 in such case?