FreeBSD-16.0-CURRENT-amd64-20260224: NFSv4.2 on Windows: mkdir fails, touch works

Hello,

some odd issue with FreeBSD 16.0-CURRENT main-n284403-895a97c875a0
(installed from
FreeBSD-16.0-CURRENT-amd64-20260224-16822dac32ab-284159-disc1.iso) and
ms-nfs41-client:
$ /sbin/nfs_mount -o rw 'F:' 'nfs://42.28.16.228//nfsdata'
Successfully mounted '42.28.16.228@NFS@2049' to drive 'F:'
$ cd /cygdrive/f/dsheldon/tmp/freebsdtests

$ touch x
$ mkdir y_dir
mkdir: cannot create directory ‘y_dir’: Permission denied

I tried this:
$ chmod a+rwx .
$ mkdir y_dir
mkdir: cannot create directory ‘y_dir’: Permission denied


No ACLs involved.
The same setup works with FreeBSD 15.0.

How can I debug this, or is this a known issue?

Dan
-- 
Dan Shelton - Cluster Specialist Win/Lin/Bsd