The bug

The banner markers feature is missing from the bedrock version of the game

Steps to reproduce:

1: Place a banner on the ground

2: Right click banner with a map

Expected result:

Banner Marker placed on map displaying the banners name if the banner has a custom name.

Actual result:

Nothing happens

Before you comment this is parity, no its a missing feature and therefore a bug. Secondly this has been reported on the Minecraft feedback site multiple times over the past few years(since the 1.13 java update) and ignored. I'm not expecting it to be added overnight but an update on when we might see it would be nice.