Every time I click on the "Share" icon in the left-hand-side toolbar, the share links are duplicated. See this screenshot:

It happens in both View and Edit modes. Reloading the page resets to one link each.

I don't think it is specific to any map, but here is one to test it: https://umap.openstreetmap.fr/en/map/long-layer-name-example_1377981

Using the French instance of uMap at version 3.6.3.