'valid users = DOMAIN\%U' worked in Samba 3.6 and stopped working at one point. Patch will follow.
Created attachment 16176 [details] patch for 4.12
Created attachment 16177 [details] patch for 4.13
LGTM.
Karolin, please add the patches to the relevant branches. Thanks!
Pushed to autobuild-v4-{12,13}-test.
This bug was referenced in samba v4-12-test: 20d3cf455c631c6cea6d471333779cc15d0e8d8a 60ddb7b20071b00f0cd7f1cb818022220eb0c279
This bug was referenced in samba v4-13-stable: 90835ba1c35ade078dc494034daeb3bf6ea02f7c 8bd284a5b36d118a26c0c17be40a03703db517d2
This bug was referenced in samba v4-12-stable (Release samba-4.12.8): 20d3cf455c631c6cea6d471333779cc15d0e8d8a 60ddb7b20071b00f0cd7f1cb818022220eb0c279