At https://cloud.google.com/translate/ , when choosing Catalan as source language, both translation into Russian and into Romanian of the Catalan “Bona Nit” are correct. Which site did you use? More detail might prove quite useful.
When selecting “detect” for the source language, there is no proper translation for Russian and Romanian.
Engineering is aware of this issue, and investigating. Note there is currently no ETA for this fix.