Why wasn't the option order executed?

Options may not be executed due to the following reasons:

1.The quotes between different exchanges are not synchronized, resulting in orders not being executed in a timely manner.

2.The minimum price change unit of different exchanges is different;

3.Since there are combination orders for options, the one-way buy and sell orders submitted may not be completed. For example, for a certain option in TSLA, if you buy one at 5.50 and sell one at 5.60, when you submit a one-way buy order at 5.50, your buy order may not be completed because the sell order at 5.50 is only part of a combination order.

4.The market is illiquid.