We see kind of inconsistent encoding problems for the vendor in Koha 3.18.2. The encoding problems appear for umlauts in the data from the database and also for the strings in the templates. Examle: Bärbel as name for the contact, or "Kontakt für verspätete Hefte" (contact for late issues). The problems are visible on the summary page and on the edit form. The problem is inconsistent, because sometimes when you open the page everything is ok... then only the database data shows the problem and the strings from the template are ok... and then both is broken. Not sure what's happening there.
Should be fixed by 11944. To fix this issue without 11944, we need to escape the string with the html_entity TT filter in the template.