Use of tags in _post news section

[laeti-tia]

I'm unsure how I should use tags in the news post I create. I did 2 trials on my last post and both somehow failed: https://www.perfsonar.net/news.html

I tried the formats:

• tags: [workshop] [callforproposals] and both the post title and the tags line were missing, as well as the link on the website front page
• tags: [workshop callforproposals] where the title and tags line are good, but the tag link is wrong and leads to a 404

What is the correct way of using multiple tags?