Blockbench cannot access certain directories when installed as a flatpak app

[steep owl]

I've been very happily using blockbench in my browser (it's awesome!), so I wanted to install the desktop app. I've been using flatpak and Linux for some time. For some reason, when installed via flatpak, the app can't seem to find files outside of the default directories within my users' /home directory (see attached image, I have more directories than what's shown.) Additionally, when I try to drag and drop the project file I want to work on, the app says it cannot find the file (see other attached image)

I've tried installing as both "user" and "system"

Thanks in advance for the guidance. Sorry if this isn't the right forum for this question.

[marsh crag]

Conflicting tags detected

It looks like you have applied tags to this post that conflict. Please only apply the tags that are relevant to your post. We can only help you if we know the context of your question, and applying incorrect tags makes this confusing.

You can refer to #1021015331910713395 for a description of what each tag is for!

Welcome to the help forum!

Please make sure to read #1021015331910713395 as it may answer your question!

Once your question has been resolved, please mark the post as closed by using the </close:1163944441741049897> command.

[steep owl]

It works as expected when installed via the .deb package

So seems to be something flatpak specific