NFS different versions of same file und different clients

Dear Group,

we recognized very strange behaviour of nfs:

Users access their files on different host through nfs4 (plain sys auth no kerberos sec).
They modify a c++ program and change parameters,
recompile it and execute it on different hosts for simulation.

We now observed that sometimes even after modifying and recompiling
the binary, an o l d version of the same binary is executed
The Binary resides on a nfs share.

  1. Write changes X to the Program and compile + execute it on PC A
  2. Write changes Y to the Program and compile + execute it on PC B

Instead of executing Program Y on PC B results and logging shows that actually the old version
(X) is executed on PC B.

Neither the problem nor the working execution is 100% reproducible.
Seems to have something to do with caching.

Regards,

j