When you use the new version of the Matomo URL builder and use all fields except the one of the keywords, the one of the keyword get automatically field with the domain name of the referrer.
If a parameter is not used, it shouldn't be filled automatically with a value.
If the keyword parameter is not used but others are: name, source, medium, content, campaign id... then the keyword field get filled.
It should stay empty.
Just use the url builder form with mtm parameters.
Hi @Chardonneaur, I tried to reproduce this on https://demo.matomo.cloud/index.php?module=CoreHome&action=index&idSite=1&period=day&date=yesterday#?idSite=1&period=day&date=yesterday&segment=&category=Referrers_Referrers&subcategory=Referrers_URLCampaignBuilder but couldn't (I also tried locally).
mtm_kwd was never present if I left the keyword field blank. Can you provide a screenshot of the problem maybe?