In the workflow editor, if you add an Input dataset collection, the "Collection Type:" shows list. No dropdown arrow appears using Firefox. A dropdown arrow appears when you mouse over using Chrome.

In Firefox, if you mouse over where the dropdown box should be, you can still click to choose "list of datasets..."

For the longest time, I thought this was broken until a co-worker showed me it works with Chrome. I'd make a Trello card for this but I can't access Trello from behind the company firewall....