Blackjack session

Put in $200 last night and had one of those blackjack runs where nothing looked wrong until it did. Dealer had an ace up a few times and i was playing like normal, one hand i had 8,8 so i split, doubled one of them, then after all that he turned over a ten and it just killed both hands and the double too. Same thing later with a decent double on 11, ace up, i take it, then dealer flips blackjack at the end. I always thought if the dealer has blackjack they check it first and the hand is dead before you start building extra money on it, otherwise it makes no sense. Maybe i'm mixing live and rng rules up but this was on a crypto site and it didn't say anything obvious on the table besides the usual blackjack pays 3:2 and dealer hits soft 17. Are there online blackjack tables where the dealer does not peek and you can lose splits and doubles to a dealer blackjack after you already put them out, or was that table just set up weird and i missed it somewhere in the rules