These are SP keycaps in DSA profile
The keycaps in top line are round stems without grooves
The keycaps in bottom line are round stems with grooves, which showed in photos
The top stem could get into switches but could not spring up normally. It seems that the stem groove locked the switches. The bottom line keycaps could be used as normal.
I email SP to say "stem get stuck in switches, the key could not spring normally"
I am not sure what is the exact description for this question? Would you please help me correct the description of this and "groove "?
Really thank you.