If you own the two nodes, the keysend is key to maintain some kind of balance in the channel and avoid this problems.

nikotsla

That was the issue, Thank you.

For anyone in the future that might read this:

In the Core Lighting web UI, goto channel details there is a "Spendable" amount.  Make sure this reads as greater than zero.  Which is different from "Maximum Send" amount which shows your whole channel size balance.  ( not reflecting the reserve amount)

Wumbo

lightning

CLN Node can not send Sats out.

> Machine2 has under 100 Sats

That could be the issue (see the buffer spec link I posted).
If is the only channel with that node try moving with keysend from node1 to node2 some more sats, try a bit more than the channel reserve (around 1%).

Yes, when you create the channel you choose between private and public and you cannot switch afterwards.