Do you use mods?
Steps to reproduce
ctrl key does not match "ctrl" it's Unknown in DST
I use Surface Pro 7 with "signature type cover" and my Desktop with Logitech-K120, B.FRiEND KB-RF800、BT300、other unknown keyboard they both Unknown ctrl in DST.
Win10 ver. 2004
with windows feature experience pack 120.2212.31.0
install DST by steam
run DST and try to input ctrl key
if still isn't happen maybe try those keyboard