LND interoperability: cooperative close attempt resulted in unilateral close

[zerofeerouting]

Issue and Steps to Reproduce

Background

Tried to coop-close a channel with c-otto.de (sister issue at LND Github: https://github.com/lightningnetwork/lnd/issues/6599).

I issued this command

lightning-cli close 733084x270x1 604800

Expected behaviour

Disabling the channel, waiting for all HTLCs to clear then coop-closing it.

Actual behaviour

Immediate force-close.

Logs

CLN logs:

2022-05-31T12:20:22.034Z UNUSUAL 027ce055380348d7812d2ae7745701c9f93e70c1adeb2657f053f91df4f2843c71-chan#4233: Peer permanent failure in CHANNELD_SHUTTING_DOWN: channeld: received ERROR error channel a97b201f22165254e8035c22f5051f37470208e5248d80bce57871bc684565cd: link failed to shutdown

LND logs:

2022-05-31 14:20:19.089 [DBG] HSWC: ChannelLink(cc654568bc7178e5bc808d24e5080247371f05f5225c03e8545216221f207ba9:1): queueing keystone of ADD open circuit: (Chan ID=0:0:0, HTLC ID=8175304)->(Chan ID=733084:270:1, HTLC ID=219854)
2022-05-31 14:20:19.168 [DBG] HSWC: ChannelLink(cc654568bc7178e5bc808d24e5080247371f05f5225c03e8545216221f207ba9:1): removing Add packet (Chan ID=0:0:0, HTLC ID=8175304) from mailbox
2022-05-31 14:20:22.240 [INF] HSWC: ChannelLink(cc654568bc7178e5bc808d24e5080247371f05f5225c03e8545216221f207ba9:1): stopping
2022-05-31 14:20:22.240 [INF] HSWC: ChannelLink(cc654568bc7178e5bc808d24e5080247371f05f5225c03e8545216221f207ba9:1): exited
2022-05-31 14:20:52.925 [DBG] NANN: Marking channel(cc654568bc7178e5bc808d24e5080247371f05f5225c03e8545216221f207ba9:1) pending-inactive

2022-05-31 14:20:22.039 [INF] PEER: unable to read message from 038fe1bd966b5cb0545963490c631eaa1924e2c4c0ea4e7dcb5d4582a1e7f2f1a5@167.235.3.234:51448: EOF
2022-05-31 14:20:22.039 [INF] PEER: disconnecting 038fe1bd966b5cb0545963490c631eaa1924e2c4c0ea4e7dcb5d4582a1e7f2f1a5@167.235.3.234:51448, reason: read handler closed

2022-05-31 14:20:22.030 [ERR] PEER: failed link shutdown: link failed to shutdown
2022-05-31 14:20:22.030 [ERR] PEER: Unable to respond to remote close msg: link failed to shutdown

getinfo output

{
   "id": "038fe1bd966b5cb0545963490c631eaa1924e2c4c0ea4e7dcb5d4582a1e7f2f1a5",
   "alias": "zero fee routing | CLN",
   "color": "1c262f",
   "num_peers": 1021,
   "num_pending_channels": 1,
   "num_active_channels": 992,
   "num_inactive_channels": 35,
   "address": [
      {
         "type": "ipv4",
         "address": "167.235.3.234",
         "port": 9735
      },
      {
         "type": "torv3",
         "address": "xtdo5qvvfwcjaruj6z4acdcw4azagn6tdgac4ajnekjdn4ghr6qw2nqd.onion",
         "port": 9735
      }
   ],
   "binding": [
      {
         "type": "ipv4",
         "address": "0.0.0.0",
         "port": 9735
      }
   ],
   "version": "v0.11.1",
   "blockheight": 738717,
   "network": "bitcoin",
   // ...
}

[cdecker]

Corresponding issue on lnd closed as a duplicate of https://github.com/lightningnetwork/lnd/issues/6039