TYPO3 Core

Here are described how the css/js merge and compress build the resulted filenames:
https://docs.typo3.org/typo3cms/SkinningReference/BackendCssApi/CssConcatenation/Index.html

I have more than one Server and they have all the same files(-sizes), same paths. However the resulted merge files at the servers are diffrent in filenames:

1. server:
merged-dbceb37e783c36e36e08a56eaa6f429d-0ac3333507d91db92390f719270f329f.css?1553494702
2. server:
merged-a0d765f8232ab798e19f30e4effe3c88-8916bf6b7d8a5e0191598561a3f26df7.css?1553494314

It seems the timestamp (filectime instead filemtime) of the files kicks in due to creating the hashs?

For example default.css:
The "merger" looks at "Geändert" instead of "Modifiziert".
If none of the concatenated/merged files are modified,
the merged-filename (hash) should stay the same?

stat default.css
Datei: „default.css“
...
Zugriff : 2019-03-26 14:41:19.000000000 +0100
Modifiziert: 2018-11-28 11:33:46.000000000 +0100
Geändert : 2019-03-26 14:41:09.000000000 +0100

Kind regards
Ralf