Using an iphone, iOS 14.6, as well as on tablet when I’m on landscape mode the mode description appears inline, even when set to tooltip.
On desktop as well as portrait mode it is fine.
When switching to description - none, it disappears.
This is intentional/expected. We only hide the forum descriptions via a tooltip on non-touch devices. If we detect a touch device, it will normally be shown. However, we also have media queries that will hide the descriptions (and a bunch of other things) by default on small devices.
There are a number of places throughout the software where we change behavior if hover events are unlikely to be available, generally by showing the content that would otherwise not be available. Equally, there are many situations where we hide information on smaller screens because there's less real estate for it. This specific situation would be a conjunction of both.
This is all controlled by the CSS, so modifications to that could be made to change these behaviors.