Ive encountered a small bug with naval builds.

1. Go to build screen. Select submarine and buy. Repeat x no. of times.
2. Cont. turn. Go through nations set to human.
3. Got to build screen again. Select submarine. Buy multiple times.
4. Do 2 as before.

Eventually some builds will show up as escort or light carrier even though the name of the unit continues using those for submarine build. Its repeateable. Over saved games as well.
Ive only tried it with subs though.

Build cost and build times show as submarine but the name of the type shows up in the queue (OOB screen) as something else. It is ofc not for every submarine builds. Only some of them.

Deploying them shows in the fleet screen, the picture of submarine (counters) but listed as light carrier or whatever.

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=937304578