Quote from: BlackHatCoiner on Today at 12:44:32 PM

(Regarding my 150,000 lost sats)

Does an hsm_secret recover non-cooperatively closed channel's funds?
As far as I understand, hsm_secret is some sort of seed for the internal on-chain wallet.

That's my understanding, too, so my answer would be yes.

Quote from: BlackHatCoiner on Today at 12:44:32 PM

However, I don't know if it can be used to recover funds with this sort of events:

Node_1 opened a 300,000 worth of sats channel with Node_2.
Node_1 sent 150,000 sats to Node_2.
Node_1 goes offline.
Node_2 cancels the channel non-cooperatively.
Can Node_1 recover the bitcoin with hsm_secret?

Yes, exactly. But there are other risks when Node_1 goes offline, due to which the funds may be lost / stolen.
Node_2 could publish an older commitment, for example.

Quote from: BlackHatCoiner on Today at 12:44:32 PM

It's not the $30, but the fact that I lost bitcoin while I'm acting very cautiously drives me crazy.

Makes sense.

Have you tried setting up a new node (maybe on testnet) and doing a backup creation / restore? If that works you may feel safer in the future.

Other things to try...
Have you tried to generate seed words from hsm_secret and restore those in Electrum?

What's odd to me is that mempool.space labels your actual force close transaction (if I understand correctly) just as a 'Multisig 2 of 2':
https://mempool.space/tx/137c7c044bd4027cde671187a1f38821a4509250b35693f3e3faa965253eb30f

Meanwhile, the address of Node_2 also got a second transaction labeled as 'Lightning Force Close' and Node_1's address still sits there with all its funds.
https://mempool.space/address/bc1qz9354tux3tzllhr2r3phktp65ghugl3sh09wjvtdl882rdf346gsgnfjxv
https://mempool.space/address/bc1qk82d4lc0fq8sy30804gwzx7qc8njydthcqp535

While you and I both know how a force close works in theory, I haven't found an actual flow graph or similar, that would definitely help explain the current situation (only one of the 2 nodes got the 'Lightning Force Close' transaction, basically).