Web server config not working for vHost Aliasdomain

short description

Web server configs (nginx / apache) cannot be selected when using vHost Aliasdomains. The dropdown is there but only contains the "-" entry. Using regular websites all expected Web Server Configs are there and selectable.

Currently the nginx (didn't tested with apache) is used from the parent. But the PHP configs ("required php snippets" from the web server config) are not applied.

correct behaviour

The dropdown should contain the configured Web Server Configs and also apply webserver AND php configs to the aliasdomains config files.

I believe this might be a regression, as I think it worked before.

environment

Server OS: Centos

Server OS version: 7.6

ISPConfig version: 3.1.13p1

screenshots

Aliasdomain (vHost) - Config missing: Website / Web Domain - Configs available: