fstat fails on nfs4 mounted filesystem (aka tar Cannot utime: Invalid argument)

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On Ubuntu 18.04-lts with hwe kernel, It seems that fstat() syscall on a nfs4 mounted filesystem reports wrong atime value. This issue is faced uncompressing a simple tar file.
Instead, mounting the same share as nfs3 all works fine.
I tried all on a ubuntu 19.04(beta) and all works fine.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-generic-hwe-18.04 4.18.0.16.66
ProcVersionSignature: Ubuntu 4.18.0-16.17~18.04.1-generic 4.18.20
Uname: Linux 4.18.0-16-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
Date: Sun Mar 17 10:20:10 2019
SourcePackage: linux-meta-hwe
UpgradeStatus: No upgrade log present (probably fresh install)

tar -zxf show the following:

tar: test.txt: Cannot utime: Invalid argument
tar: Exiting with failure status due to previous error

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Testing tar archive.

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tar output on NFS4 filesystem (failing utime)

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Verbose strace of tar -zxf test.tar.gz on NFS4 (failing ftime syscall)

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Verbose strace of tar -zxf test.tar.gz on NFS3 (working ftime syscall)

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s/ftime/fstat/g sorry