Bitnami is great for many things, but they don’t update their images often enough to be able to keep up with Discourse (and docker) updates. As a result you’re really on your own as far as support and maintenance is concerned. I learned this the hard way myself.
While I know this is not ideal, I’d recommend you move your installation to one that’s supported by the Discourse community. You can find suitable hosting here, here or here, build a clean image, install docker, install discourse and import the existing community via the discourse backup/restore function.
It’ll be worth it in the long run.