Okay, seems like we need to use correct proxy. Here is a small startup-script that installs dependencies using maven 3.9.9! Same can of course be done using mvnw, this is just simplified (and not yet fully optimised, more a proof of concept):
#!/bin/sh
version=3.9.9
url="https://dlcdn.apache.org/maven/maven-3/${version}/binaries/apache-maven-${version}-bin.tar.gz"
echo $url
wget $url
sleep .4
tarFile="apache-maven-${version}-bin.tar.gz"
echo $tarFile
sudo tar -xvf $tarFile -C /opt/
export PATH=/opt/apache-maven-${version}/bin:$PATH
echo -e "\nPATH=\"/opt/apache-maven-${version}/bin:\$PATH\"" >> ~/.profile
mkdir -p ~/.m2 && cat > ~/.m2/settings.xml <<EOF
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
https://maven.apache.org/xsd/settings-1.0.0.xsd">
</settings>
EOF
sed -i '/<\/settings>/ i\
<proxies>\
<proxy>\
<id>defaultProxy</id>\
<active>true</active>\
<protocol>http</protocol>\
<host>proxy</host>\
<port>8080</port>\
</proxy>\
<proxy>\
<id>defaultSecureProxy</id>\
<active>true</active>\
<protocol>https</protocol>\
<host>proxy</host>\
<port>8080</port>\
</proxy>\
</proxies>' ~/.m2/settings.xml
mvn dependency:go-offline -X