Hi @Flitskikker,
What names do your artifacts have before they are uploaded to Bintray (on your file-system)? I'm asking this because the Bintray Plugin simply collects the artifacts from the defined Configurations (the "archives" Configuration for example).

i happen the same problems,and i found some founds.
Firstly,

you must renamed the androidSourcesJar and androidJavadocsJar of name . and you will get correct androidJavadocsJar and androidSourcesJar.
so i try to renamed the outputFile's name.like this,

and then , i think i resolve the problems and print all files of the "archives" Configuration like this,

and gradle print message :
files length 3
files mixdpic-1.0.5-sources.jar
files mixdpic-1.0.5-javadoc.jar
files mixdpic.aar

now, i think i can upload correct arr'file.but!!!!!!!!
when i exec gradle clean bintrayUpload --info ,i found some problems!!!!!!:

just you see ,the name of aar is still module's name-aar。
this is bug？

ok,finally,i solve the problem like this!!!!
the method is simple.i just create configuration named "jcenter_upload" like this configurations.create("jcenter_upload")
and then configure install like this

and configure artifacts

finally

you can see my project

ok，i find a simple method, you just set the value of project.archivesBaseName to your POM_ARTIFACT_ID

Facing the same issue