When a canonical path is not specifed, scp should have the base path be the home of the current user.

scp -r ./folder coder.env:.cache/JetBrains/Fleet
scp: stat remote: No such file or directory

scp -r ./folder coder.env:/home/coder/.cache/JetBrains/Fleet works fine.

I have checked and this SCP behavior is functional over regular SSH.
This is causing JetBrains Fleet to not work remotely.