This article provides a solution for the issue when all error messages on the storefront display with a “+” sign instead of a space. This solution helps error messages remain readable.
Steps to reproduce:
The issue is caused by a PHP 7.4.2 issue related to set\read cookies. See PHP BUG #79174 setcookie() encodes space as `+`, but $_COOKIE no longer decodes them.
To solve this issue, use another version of PHP 7.4.x. PHP 7.4.2 is not supported by Adobe Commerce 2.4.0.