Problem with substring search with German umlauts RH2019.0.12 new UI HTML5 output

Hi all,

I have a problem with the substring search in the HTML5 output. I am using RH2019.0.12 new UI, but the problem also occured with update 11. The search settings for my output are as follows:

Use topic description = true

Enable auto complete = true

Auto correct search query = false

Show definitions from glossary = true

Enable substring search = true

Add special characters for search = false

Generate XML sitemap = false

In my output, I have several topics containing the word "Primäreinzelkosten". If I search for "primär", I only get results containing exactly the word "primär", but not the "primäreinzelkosten". If I search for "primä", I get no results at all. If I search for "prim", I get all topics containing "primär", "primäreinzelkosten" and "primrose" or whatever. So the substring search seems to have a problem with the "ä". The substring search works as expected for example when searching for topics containing the word "Kostenblock". They are found whether I search for "koste", "kosten", or "kostenb".

My project language is set to German, my output language is also set to German. I tried outputs with the following Encoding settings: Default Encoding, Westeurope(ISO), UTF-16, UTF-8 without BOM. I also tried the outputs in different browsers (Chrome, Edge, Firefox). No matter what, I do not get any results when searching for "primä".

Does anyone know if there are further settings that I can check in order to make this work? Or is this a bug? In this case, I will create a bug regort.

Thanks and regards
Karin