Looking at the main contract generally depends on the volume and position. Now the positions of 1309 are beginning to decrease, indicating that the main force is gradually moving positions. When there is little difference between the two, it doesn't matter whether the main contract or the second main contract is traded.

As for you jumping up and down, the reason is that there are many people trading in the main contract, so the price changes are continuous, but there will be slippage under extreme market conditions. Instead of the main contract, especially the inactive contract, because there are very few people involved in the transaction, the price that the trader is willing to close is inconsistent, and the price of each match will be very different, which is what you said.