Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes
OS: Windows 10 | CPU: i5-9600K @ 3.7 GHz | GPU: Nvidia GeForce GTX 970 | RAM: 16GB
I'm seeing the same issue as well. A standard Mk 1 "Tin Can" with a heat shield and parachute attached shows no marked deceleration if the re-entry starts with just those parts. Time warp status doesn't seem to affect anything.
However, if I leave the rest of my craft attached at the start of re-entry, and let those parts burn off, then deceleration of my tin can + heat shield works as expected.