Is 2 enough to assume that the transaction was dropped by the network? I am asking, however I must say, I actually tried to re-send the UTXO (not sure I am using the term correctly) 9 days ago.
With how the nodes relay and drop transactions nowadays, it's hard to assume that a txn is totally dropped by the network since it might propagate again in the right condition.
Reason is, not all nodes has the same relay and mempool settings, some of those may keep a transaction indefinitely and some wallets are re-broadcasting transactions.
Specially yours that's only unavailable in two blockexplorers,
I bet that it'll be relayed back to your server's mempool once its fee rate made it in the default relay fee policy.
Although, it will get dropped for good once any of its input is spent by another transaction.
I have a receiving transaction showing as "Local" in Electrum, so, I understand no longer on the network.
Unfortunately, since it's inbound, you can't do anything to it but to contact the sender to increase the fee if it's possible in his wallet;
Or wait for it to be able to broadcast again then use CPFP to the transaction to bump its fee (
right-click->"Child pays for parent"),
Alternatively, instead of CPFP, use "
coin control" (
instructions) to use its output to your next transaction but set a higher fee rate to bump those two txn's overall fee rate.