I can't find Subspace compression Coil cause the planet it has been detected I always end up in a cave in the event "the spaceship accidentally warped to somewhere below surface". How can I fix this ?

Well I search for a cave exit but... I give up, I'm blocked by this bug I guess

A bug.. working on a fix

Fixed, but I'm afraid will will have to warp and then come back

I confirm it's fixed, thx a lot for your help.

I've run into the same issue with the Subspace compression Coil being on a planet where I only warp underground, but updating and then warping away/warping back did not resolve it for me. I just ended up consoling it in after finding this thread, but wanted to give you a heads up that it might not be fixed for everyone

Do you know how to find such item on not cave planet in the first place ?

If I understand your question correctly, I normally just "Search Surface" when I'm on a planet with an Artifact to find the Outpost Assembler.

then I suggest you upload your save so ferrari could take a look

have you warped to this cave after the mod update where i fiexd this issue? if yes, add a link to the saved file here, and I can check what is going on