Upload dialog shows elements from previous upload

[aquarix]

What steps will reproduce the problem?

1. Download a region, edit some elements and upload it
2. Delete the current data layer, move to another place and download a region there
3. Again edit one object and click the upload button

What is the expected result?

The upload dialog should show one modified object in the list and the summary should indicate whether the objects are added, modified or deleted.

What happens instead?

The upload dialog shows the objects of the previous changeset upload. After clicking into the list the changed object of the current changeset gets shown but the rest of the list is visible as before but you cannot click on it.
The summary line over the list is also wrong. It says "1 object for deletion" but currently I only modified one object. The "1 object for deletion" was true 2 changesets before.
This behavior already occurred at the changeset upload before but I didn't realize it as an obvious error.

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

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-02-01 01:10:57 +0100 (Sat, 01 Feb 2020)
Revision:15806
Build-Date:2020-02-01 00:12:46
URL:https://josm.openstreetmap.de/svn/trunk

Identification: JOSM/1.5 (15806 de) Linux Ubuntu 18.04.4 LTS
Memory Usage: 835 MB / 1234 MB (281 MB allocated, but free)
Java version: 11.0.6+10-post-Ubuntu-1ubuntu118.04.1, Ubuntu, OpenJDK 64-Bit Server VM
Screen: :0.0 1680x954
Maximum Screen Size: 1680x954
Java package: openjdk-11-jre:amd64-11.0.6+10-1ubuntu1~18.04.1
Java ATK Wrapper package: libatk-wrapper-java:all-0.33.3-20ubuntu0.1
libcommons-compress-java: libcommons-compress-java:all-1.18-1~18.04
libcommons-logging-java: libcommons-logging-java:all-1.2-2
fonts-noto: fonts-noto:all-20171026-2
liboauth-signpost-java: liboauth-signpost-java:all-1.2.1.2-1.5
VM arguments: [-Djosm.restart=true, -Djava.net.useSystemProxies=true]
Dataset consistency test: No problems found

Plugins:
+ FixAddresses (35248)
+ HouseNumberTaggingTool (35248)
+ OpeningHoursEditor (35250)
+ buildings_tools (35248)
+ imagery_offset_db (35248)
+ reverter (35313)
+ turnrestrictions (35313)
+ undelete (35313)
+ utilsplugin2 (35248)

Tagging presets:
+ https://josm.openstreetmap.de/josmfile?page=Presets/Historical_Objects&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Heritage&zip=1

Map paint styles:
- https://josm.openstreetmap.de/josmfile?page=Styles/Enhanced_Lane_and_Road_Attributes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Maxspeed&zip=1

Last errors/warnings:
- W: JCS TMS - error loading object for tile 15/17451/11404@OpenStreetMap Carto (Standard): Error reading PNG image data
- W: JCS TMS - error loading object for tile 15/17451/11404@OpenStreetMap Carto (Standard): Error reading PNG image data
- W: JCS TMS - error loading object for tile 15/17451/11404@OpenStreetMap Carto (Standard): Error reading PNG image data
- W: JCS TMS - error loading object for tile 15/17451/11404@OpenStreetMap Carto (Standard): Error reading PNG image data
- W: JCS TMS - error loading object for tile 15/17451/11404@OpenStreetMap Carto (Standard): Error reading PNG image data
- W: JCS TMS - error loading object for tile 15/17451/11404@OpenStreetMap Carto (Standard): Error reading PNG image data
- E: Fehler beim Laden des Bildes 'https://code-de.org/sites/all/themes/cde/favicon.ico'
- E: Fehler beim Laden des Bildes 'https://code-de.org/sites/all/themes/cde/favicon.ico'
- E: Fehler beim Laden des Bildes 'https://code-de.org/sites/all/themes/cde/favicon.ico'
- E: Fehler beim Laden des Bildes 'https://code-de.org/sites/all/themes/cde/favicon.ico'

[aquarix]

Screenshot of JOSM upload dialog with wrong modify list

[aquarix]

Screenshot of JOSM upload dialog with list OK again

[aquarix]

Interesting is also that the upload and cancel buttons seem to be pressed both at the same time.
The curious thing is:
If you press the cancel button the upload dialog closes as you would expect it.
After you only hover over the upload button with your mouse the list looks correct again as if nothing ever happened.

Please compare both screenshots then you will get what I mean.