As far as I understand, djhomeschool got it correctly. Essentially if your transaction was considered as dust by other (almost every) nodes then it won't get transferred, therefore it won't reach the mempool.
However, judging from your case, I assume you're consolidating a lot of small input and then send it as a single output, is this right? Then it should not be considered as dust imo as long as your fee is high enough. Anyway, you can read more about this case here:
https://bitcointalk.org/index.php?topic=2637574.0Maybe one of your input is already spent. Can you post any raw data?
Okay, I will post raw data a bit later.
Right, I'm trying to consolidate a lot of small input, but then bitcoin core writes error "transaction too large". After that, I tried to send a small amount like 0.01 BTC with priority fee and it still writes not in memory pool.
So, is there any opportunity to send bigger amount and solve a problem with "not in memory pool".
Regarding the case, i see that it looks like the same situation as mine, but don't fully understand steps to solve it. Maybe you can expain?