A tlx template in which one of the parameters contains a URL renders the following pipe symbol in hexadecimal (%7C). See https://en.wikipedia.org/wiki/Template_talk:Tlx#Improper_rendering_of_|_following_URL for discussion. Below is a minimal example that I have tested at https://test2.wikipedia.org/wiki/
{{tlx|cite web|2=url=http://www.example.com/ |3=title=Example web page }}
@Chatul this sounds like an issue with on-wiki template, not the mediawiki software. Closing accordingly
Hi @Chatul, thanks for taking the time to report this and welcome to Wikimedia Phabricator!
On-wiki content like user scripts, gadgets, templates, custom CSS are local features and managed independently on each wiki. You could contact previous authors of local pages (see "View History") or discuss on a corresponding talk page or local village pump. This problem needs to be discussed and fixed on the local wiki instead of Phabricator (as local content on wikis is out of scope for Phabricator), hence this task was closed by Danny.