Potentially wrong calculation?

[Norushmath]

Under the Rule below, when calculating the split-EV of dealer 10, player 3,3
The 2C strategy gives -0.641948
The Optimal strategy gives -0.641977
Which is strange because optimal strategy is supposed to be better than or at least equal to the 2C strategy, yet here the optimal strategy gives a worse EV. Similar result happens for dealer 10, player 2,2 and dealer 10, player 4,4.

Rule:
Deck: 8
Dealer Stands on soft: S17
Dealer Blackjack Rule: ENHC
Double Allowed: DOA
Double After Split: False
Surrender Allowed: None
Splits Allowed: SPL1
Blackjack Pays: 1.5
Allowed to Split Multiple Aces: False
Hit after Split Aces False
Double Split Aces: False
Double Any Number
Doubled Soft Totals Count as Hard False
CD Splits Type: CDZ-
BJ Bonus to Split Tens: False
BJ Bonus to Split Aces: False
Dealer Checks Under Tens: False
Dealer Checks Under Ace: False
Bonus Rules Used: None
Forced Rules Used: None