Same issue here, after a bit of inspecting it appears that this is only affecting radio buttons for me at the moment and only on some sites across various different WP versions, no multisite and latest ACF version.
Any newly duplicated blocks inherit the copied block settings but the settings in the original block are removed when doing this.
I’m not sure if this is the actual issue or intended behaviour but the additional fields inside the block are all inheriting the same data-block-id value. Block ID’s are all still unique though.
<div class=”acf-block-fields acf-fields” data-block-id=”block_b2d072f5-ef0d-48ad-92c7-6e3ad9a30fd0″>
