Is there any known limitation to the contents of the grpc preshared key? I tried

9o5Nnk93O8Am$isH%G#Fav6$7g!cdnP%W0S@E!s2Q7nU$6hrDVIR4Ss4OtTsnhue

and was getting errors in

zed

about an incorrect key, but using an alphanumeric key seemed to work. I'm using the docker image in k8s.