The total node you might be working doubtless has the usual mempool dimension (300 MB) and default settings. In the meanwhile (see e.g. https://mempool.area/), transactions with a payment lower than 5.88 sat/vB are purged from the mempool.
In your case, the 2 transactions from the SPV pockets that had very low charges (1 and three sat/vB) had been doubtless not accepted into your full node’s mempool as a consequence of this payment threshold. Nevertheless, these transactions had been nonetheless propagated via the bitcoin community, as they had been accepted by one other node that accepted transactions with a decrease minimal payment charge. This node in flip relayed the transactions to different nodes, ultimately reaching the Blockchair node.
In consequence, these two transactions at the moment exist solely within the mempools of sure full nodes which have a decrease minimal payment charge, which is why you possibly can see them on the Blockchair explorer however not in your full node.