Acrobat 26.07.51 on iPad intermittently fails to open local PDFs

Hello, I am experiencing significant problems with Adobe Acrobat on my iPad.

Device: iPad Pro 11-inch (4th generation)
iPadOS: 26.6
Acrobat version: 26.07.51 (build 20260818.120342)
Subscription: Acrobat Premium

Since around August 28, 2026, some PDF files that previously opened normally have started failing to open directly from Acrobat → Files on iPad.

The files are stored locally under Files → On My iPad. Some PDFs open normally, while others do not. The problematic PDFs open immediately in Apple’s Files app. They also open successfully if I use Open With → Acrobat.

The problem is intermittent: sometimes the same PDF opens only after many attempts.

This does not appear to be simply a file-size issue. PDFs of approximately 1 MB and 30 MB open normally, and a 57 MB test PDF also opened normally. One problematic PDF is approximately 242 MB.

In addition, Acrobat has been extremely slow for quite some time when opening, copying, and moving files.

These PDFs contain important comments and annotations, so converting them to images or flattening them is not an acceptable workaround.

Please let me know whether this is a known issue with Acrobat 26.07.51 on iPadOS 26.6 and whether there is a recommended fix or newer build.