A recent update to the Jira Cloud UI has removed text wrap from the Epic summary (title) that is dislaied in the left-nav, Epic panel that can be enabled in the Backlog area of a board.
This has a significant negative impact on usability - or to put it another way, for Epics with more than a short title, it's totally unusable any more.
Before - Epic title text wrapped in the left panel so it was readable

After - if Epic title is longer than about 21 characters, it is truncated

...sure, we all strive for nice brief Epic titles but there are scenarios where this is not the case, with this new UI change, the function of the Epic Panel is almost completely trashed.