I’m seeing the same issue on w/ iPhone SE (Gen 1) on iOS 13.3.
Unfortunately, I didn’t save a copy of the old .ipa
Obsidian logo followed by blank screen, no way to access any menus, content, etc.
Is there any regression testing performed on older iOS versions? As OP mentioned, many older devices cannot be updated to newer iOS versions and delegating an older device for simple tasks like note-taking with Obsidian makes sense.
I cannot check if it happens on a new vault because I can’t change the vault or create a new one. After the logo there is no operability whatsoever.
My guess is that something with Canvas requires something in the newer iOS versions. I’d be willing to live without Canvas if I could keep using Obsidian on my iPad. But the Canvas thing is just a guess.
I just used my desktop to create a new vault in my iCloud Drive and can see the folder on my iPad, but the app still opens to a black, inoperable screen. Tried forceclosing the app, restarting the iPad and reopening app, but the experience is the same - logo and then nothing.