pushing charts fails - encryption method issue

Hi, i'm breaking my head over this problem with chartmuseum and can't find any issues on this.
i configured chartmuseum on my aws environment and everything seems fine (the url shows the welcome page, all pods have no errors)
I configured a directory in my computer to serve as a repo, as instructed.

when i try to push the charts (.tgz) to the chartmuseum, i get an error:
```Pushing kong-0.1.0.tgz to chartmuseum...
Error: 500: InvalidArgument: The encryption method specified is not supported
status code: 400, request id: xxxx, host id: xxxx
```
_*xxx mark sensitive data_

**steps i did to try and solve this:**
- unpacked the .tgz files and repacked them (error still shows)
- used helm push with --force, --insecure
- tried to send the charts with curl, wput, repo update and helm push
- re-initialize the helm client

did anyone encounter this error?
I ran out of ideas regarding how to fix this, any ideas would be great
Thanks!