Image Upload Frontend no longer working

On (at least two tested) websites it appears no longer possible to upload avatars or canvas images in the front end.

The tabs for canvas and portrait do appear and offer the option for uploading a new image or choosing from the galery in the select field. But nothing happens, i.e. the actual upload procedure (or galery selection) does not start.

Any thoughts on what I am missing? (it used to work - but I don't know for how long the function is broken)

Joomla 3.9
PHP 7.1 and 7.2
CB 2.2.1

CB 2.2.1

Please ensure you've the latest build release installed. Latest is 2.2.1+build.2018.11.01.17.21.41.e3e5bf527. If issue persists switch to default Joomla protostar template and retry to rule out template conflicts.

Thanks for your feedback.

Unfortunately neither solution brought the desired result.

If the template is the culprit, I guess I need to deinstall the framework as well to test protostar... Or are there other thoughts? (don't want to mess too much with a very live website).

EDIT:
deactivated framework, switched to protostar ... problem still persists.

So you select that you want to upload a image, you click the browse button and find the image you want to upload, you select the image, then you click Update, it then saves the profile, but the image you selected isn't uploaded. Is this correct? if not please provide exact steps of where it's failing. If the profile does successfully update it might be something PHP side. If it doesn't then it maybe JS related. To check for JS related press F12 to open your browsers developer tools, click console, then refresh the page. Now check if there's any fatal (they'll be red) JS errors present before and during image upload attempt.

actually ... no.
When I select "Upload Avatar" (select from galery, for that matter) that field appears in the selection field. But ther browser button to select a picture or the lightbox for existing avatars do not appear - i.e. nothing happens.

I assume it's some kind of js problem - but unfortunatley ... I am too much of "lay person" to know what to do...

Thanks.

Switch to default Joomla protostar template, clear Joomla cache, then retry to see if it's a possible JS issue coming from your template. If issue persists ensure everything installed (CB, CB plugins, and other extensions) is completely up to date then retry. If issue still persists press F12 to open your browsers developer tools, now click the Console tab, next refresh the profile edit page and try to use the dropdown and see if any fatal JS errors are present in the console (they'll be red).