I have 3 services connected to a Postgres-DB.

I connected them using the "Want ot connect a Database? Use a Variable!"-link to ensure the correct syntax.
It worked (arrows in the architecture view) until now. I did not change anything but the arrowas are gone.
Restarting, Redeploying, deleting variable then rentering the variable - all didn't help.
Also a totally different project with 6 services and a postgres DB - which i did not touch for days - has now the same problem: no service is connected to the db anymore.

What might be the cause of this behavior? How can i ensure that my services get reconnected to the database?