I have MiniMap set to show radar and hydro ranges for enemy ships. When working correctly (using my custom set colors,) it looks like this for a ship with hydro and radar:
A ship with just hydro looks like this:
A ship with just radar:
(this is showing the radar for Yueyang only)
US ships show nothing:
I do not have it set to show other range rings (detection, AA, etc.) ordinarily, but checked those in the training room and they all work:
I checked at least one tech tree ship for each nation with radar and hydro and confirmed they work.
ETA: I confirmed the other range rings for U.S. cruisers (Baltimore and DM) do work, not just the DD and Montana. So the extent of the problem is radar and hydro range rings, U.S. cruisers. It may also affect Black, Missouri, Constellation and premium cruisers as well, but I cannot add premium ship bots to the training room to see.