Jira custom field with unexpected behaviour after upgrade

Hi team.

We have recently upgraded our production instance to the last LTS version and we noticed a weird behaviour on one of our custom fields, which now appears to “float” along the page after scrolling.

This field is a text field (single line) that gets modified by the following JS code:


We suspect that the changes to the AUI made in Jira 8 might be behind this (The field was behaving correctly before the upgrade on Jira 7).

Any idea on how we could work around this?