Not just the last few versions - it has been like this since the code node was introduced :)
The reason is that the code node is a bit of an exceptional case, because it's the only node that needs to be compiled separately if it should ever have a preview. That's not to say that it's impossible, but it's harder

Not sure why the picture is down! In any case, this should help:

It could be related. The problem with "just updating" is that Unity will never remove any assets on update, which means that if I delete something in SF, and you just patch on a new version, you'll still have the files that I deleted.

A full reinstall is always the safest route to go - I recommend trying that with the latest version :)

This should have been fixed as of 1.23, which version are you on?

It was not intentional, and I'm not getting the issue here :(

Not sure what could cause it

This has now been fixed in 1.23

As of 1.23, you can no longer "just" hide them, disabling scale/offset will now both hide and remove them from the shader calculations :)

Seems like a bug they should fix on their end, no?

This has now been fixed in 1.23. The bug happens when any of the two values are zero. For now, you'll need to make both non-zero :)

I'll have to look into this, thanks for the report!