Send mail address is username@hostname (maybe empty)

Question

I have a multiple site / scope configuration on Magento 2.4.2. All Send-from (and Return-Path) addresses like order confirmation etc. that Magento sends are always username@hostname. Found a issue on https://github.com/magento/magento2/issues/14952 but this helps ot for the Magento 2.4-*. How to show send-from addresses correctly?

Magento 2.4.2