Can someone explain to me why my stops did not trigger?

Hi there,

I was holding BTC on Bybit and Bitmex exchange.
I rode it up from about 9k, to 14k,
I wasn't using leverage, just holding.

I set a short stop-loss at 13300 for 1x my portfolio value in BTC/Dollars.
So, I had about 0.2BTC and I set a stop for about 0.195 BTC in order to hedge my dollar value against the crash (which happened ofc)

However, My stoploss was 'rejected'. On both exchanges.
I have no idea why.
I did not have 'close on trigger' selected as this would have understandably rejected my order on execution as it would have reduced my position from 0 to -$2800 (which would have been adding a position not closing one - Is that correct?)

So, as a result of my stops not triggering. I didn't lock in any profit from that rise and am back where i started... same amount of BTC but no extra $$ value, and no hedge.
What did I do wrong? or did both exchanges screw me?
I've been talking to other traders and it appears the stops didn't work for many of them last night.

I'm really annoyed, and I can't work out what I did wrong. Should I have used 2x leverage with my stop-sell, to account for any slippage and me not having enough margin? I'm so confused.
Please advise.
Regards,
TG