On the Librem 5, the BLuetooth panel of the Settings app is too wide. The issue was fixed almost a year ago and is available since version 3.29.1, but PureOS Amber ships 3.28.2. Backporting a newer version from Debian Unstable would likely fix the issue.
See https://source.puri.sm/Librem5/gnome-control-center/issues/83.