If i enter a search value with whitespace like "delay filter" it encodes the whitespace and searches for "delay20filter" which clearly not works.
Can some else confirm this behaviour?
Yes, that is correct.
However it is not an issue. It is because the Reaktor forum is very old (it is not part of this forum, they only connected by links) and its code language is also old.
At that time, (ages ago 😋), the number 20 represented the empty space.
In the earlier days of the internet, they decided that URLs should only have a certain set of letters and punctuation allowed in them. Spaces weren't one of those. But people still wanted to communicate things like spaces in URLs, even though they couldn't actually put a space. So they decided that you could use a percent sign (%) plus the ASCII number of the thing you actually wanted. So wherever in a URL that you want to communicate a space, you can put "%20" and whatever program is looking at the URL will know that a space should go there.
So, that "20" in the Reaktor forum search is a relic of that period. It can not be changed or fixed. The only solution is a new forum…
the issue is in the userlibrary search-form, not the forum and i already pointed out, that it seems to be a whitespace encoding issue. such things should fixable very easy. just try a search to reproduce the issue for yourself.
Forum search works fine.
I think you got confused. I understood perfectly what you wrote. I did not meant this forum but the Reaktor forum (obviously, since your post has to do with it: UL = User Library).
Reaktor user library is a forum too, just too old, and has nothing to do with this forum, it is a separate space. Its search-form is ancient, so it does has this annoying behavior (i explained it on my first comment).
"just try a search to reproduce the issue for yourself."
…i have used this search-form hundreds of times, since 12-13 years already… 😋
I found a workaround, use a minus instead of whitespace works. If i search for my Bytechop Layersampler the search URL looks like:https://www.native-instruments.com/en/reaktor-community/reaktor-user-library/all/all/all/785649/bytechop%20layersampler/latest/1/all/?q=bytechop%20layersampler&t=userlib
https://www.native-instruments.com/en/reaktor-community/reaktor-user-library/all/all/all/785649/bytechop%20layersampler/latest/1/all/?q=bytechop%20layersampler&t=userlib
Field value is now: bytechop20layersampler
https://www.native-instruments.com/en/reaktor-community/reaktor-user-library/all/all/all/785649/bytechop+layersampler/
Field value was set to: bytechop-layersampler
It seems, that there a two different url encodings in use, who are causing this failure.
The UL is running a outdated Typo3 8.x which has possible issues with the indexed search extension.