Validator marks adresses from different suburbs as duplicate

[MindSolve]

What steps will reproduce the problem?

1. Download the OSM data for the follwing OSM URL: ​https://www.openstreetmap.org/#map=16/54.2047/10.5775 (containing the two villages "Malkwitz" and "Sieversdorf")
2. Start the validator
3. Notice (at least) two "duplicate housenumber" warnings, where the one address is in Sieversdorf (tagged with addr:suburb=Sieversdorf) while the other is in Malkwitz (tagged with addr:suburb=Malkwitz)

What is the expected result?

The warning does not appear, as ​https://wiki.openstreetmap.org/wiki/Key:addr:suburb is specifically made for resolving such a conflict.
(I hope I am not wrong with that ;)

What happens instead?

The "duplicate housenumber" warning appears, even though the addresses are in different suburbs.
This also happens if both the street and the housenumber-wearing object have addr:suburb set.

Please provide any additional information below. Attach a screenshot if possible.

I don't know any way, how a screenshot would be useful here.
If anybody needs a screenshot of someting specific, I will happily oblige.

Also: I am using JOSM in German (the validator message is "Doppelte Hausnummern").

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2019-04-28 04:36:41 +0200 (Sun, 28 Apr 2019)
Build-Date:2019-04-28 02:37:58
Revision:15031
Relative:URL: ^/trunk

Identification: JOSM/1.5 (15031 de) Windows 7 64-Bit
OS Build number: Windows 7 Home Premium (7601)
Memory Usage: 1384 MB / 1820 MB (399 MB allocated, but free)
Java version: 1.8.0_201-b09, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: \Display0 1920x1080
Maximum Screen Size: 1920x1080
VM arguments: [-Djava.security.manager, -Djava.security.policy=file:<java.home>\lib\security\javaws.policy, -DtrustProxy=true, -Djnlpx.home=<java.home>\bin, -Djnlpx.origFilenameArg=%UserProfile%\Downloads\josm.jnlp, -Djnlpx.remove=false, -Djava.util.Arrays.useLegacyMergeSort=true, -Djnlpx.heapsize=NULL,2048m, -Djnlpx.splashport=50920, -Djnlpx.jvm=<java.home>\bin\javaw.exe]
Dataset consistency test: No problems found

Plugins:
+ OpeningHoursEditor (34977)
+ RoadSigns (${version.entry.commit.revision})
+ TombPlugin (58)
+ apache-commons (34908)
+ apache-http (34908)
+ areaselector (349)
+ austriaaddresshelper (57)
+ buildings_tools (34982)
+ ejml (34908)
+ fieldpapers (v0.5.0)
+ geojson (124)
+ gson (34908)
+ indoorhelper (34977)
+ jna (34908)
+ livegps (34977)
+ log4j (34908)
+ mapdust (${version.entry.commit.revision})
+ measurement (34977)
+ openqa (1556817162)
+ print (34972)
+ splinex (34908)
+ tag2link (34977)
+ terracer (34977)
+ wikipedia (v1.1.1)

Tagging presets:
+ https://josm.openstreetmap.de/josmfile?page=Presets/Communication_Towers&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Camp_site_extends&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/BAR-damage-assessment&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Playground_Equipment&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Historical_Objects&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/StreetCabinet&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Manholes&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/MobilePhoneBaseStations&zip=1
+ https://www.openrailwaymap.org/josm-presets/de-signals-bostrab.zip
+ https://www.openrailwaymap.org/josm-presets/de.zip
+ https://www.openrailwaymap.org/josm-presets/de-signals-eso.zip
+ https://josm.openstreetmap.de/josmfile?page=Presets/OpenStationMap&zip=1
+ https://raw.githubusercontent.com/yopaseopor/traffic_signs_preset_JOSM/master/DE.zip
+ https://josm.openstreetmap.de/josmfile?page=Presets/Trees&zip=1
+ https://osmtools.de/josm/steps.xml
+ https://josm.openstreetmap.de/josmfile?page=Presets/WifiHotspots&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Surveillance&zip=1

Map paint styles:
- <josm.pref>\styles\sit.mapcss
- https://josm.openstreetmap.de/josmfile?page=Styles/Fixme&zip=1
- https://pasharm.github.io/New_basic_style_for_JOSM/New_basic_style.mapcss
+ https://josm.openstreetmap.de/josmfile?page=Styles/PowerMapping&zip=1
+ https://raw.githubusercontent.com/yopaseopor/traffic_signs_style_JOSM/master/Styles_Traffic_signs_EUR.zip

Validator rules:
+ https://josm.openstreetmap.de/josmfile?page=Rules/GermanySpecific&zip=1
+ https://www.openrailwaymap.org/validator/de-openrailwaymap.validator.mapcss

Last errors/warnings:
- E: Defekte Vorlage "surveillance-kind of surveillance" - Die Anzahl der Datenworte in 'display_values' und in 'values' müssen gleich sein
- E: Detaillierte Information: [Innenräume, Außenbereich, Öffentlicher Raum, Webcam, ja (irgendeine Art von Überwachung), nein (keine Überwachung)] <> [indoor, outdoor, public, traffic, webcam, yes, no]
- E: Defekte Vorlage "surveillance-kind of surveillance" - Die Anzahl der Datenworte in 'display_values' und in 'values' müssen gleich sein
- E: Detaillierte Information: [Innenräume, Außenbereich, Öffentlicher Raum, Webcam, ja (irgendeine Art von Überwachung), nein (keine Überwachung)] <> [indoor, outdoor, public, traffic, webcam, yes, no]
- W: No configuration settings found.  Using hardcoded default values for all pools.
- W: Region [WMS_BLOCK_v2] Resetting cache
- W: Region [WMTS_BLOCK_v2] Resetting cache
- E: java.lang.ClassNotFoundException: controller.IndoorHelperController

[Don-vip]

In 15043/josm:

fix #17674 - use addr:suburb to distinguish similar addresses in the same city, like addr:postcode