Area: macOS 26 Tahoe – Save / Export Dialog with Indesign

Summary:
In macOS 26 Tahoe, the Save As filename field does not pre-populate when opening a Save As or Export dialog in Adobe InDesign. When manually retyping the filename, if the name contains a period followed by a space, the entire field is cleared the moment the space is typed. This does not happen with filenames that contain no period. No known workaround resolves this.

Steps to reproduce:
1. Open a document in Adobe InDesign whose filename contains a period (e.g. "April 12.26Quarter Page HorSN.indd")
2. Go to File > Export or File > Save As
3. Observe that the Save As field is blank — the filename is not pre-populated
4. Begin manually retyping the filename, including a period (e.g. type "April 12.26")
5. Type a space after the period
6. The entire contents of the Save As field are immediately erased

Additional reproduction path (no workaround exists):
Even when clicking directly on the original InDesign file in the Save As dialog to repopulate the filename field, the bug persists. As soon as any character is typed at the end of the pre-filled name (e.g. typing "" to append "Proof"), the entire filename is instantly wiped. Because every file in our workflow contains a period (we date all files using a month.year format, e.g. "4.26"), there is no way to avoid triggering this bug. Every save attempt is affected.

Expected behavior:
- The Save As field should pre-populate with the current document filename
- A period followed by any character should be valid input in a filename field
- Appending characters to a pre-filled filename should not clear the field
- This worked correctly on macOS 15 Sequoia and earlier

Actual behavior:
- Save As field opens blank regardless of the current document name
- Typing a period followed by a space clears the entire field
- Clicking the file to repopulate the field and then typing any character also clears the field
- This only occurs when the filename contains a period — filenames without a period are unaffected

Additional observation:
The bug appears to be isolated to filenames containing a period. This suggests macOS may be misinterpreting the period as a file extension delimiter and rejecting any character that follows as invalid, causing it to reset the entire field.

Impact:
This is a critical workflow disruption. All of our work files use a month.year date format (e.g. "4.26") in the filename, meaning 100% of saves are affected with no viable workaround. Tasks that previously took minutes are now taking three times longer. This issue began immediately after updating to macOS Tahoe two days ago and has been unresolvable since.

Comparative note:
Colleagues who received new Macs with Tahoe pre-installed are not experiencing this issue. It appears to affect Macs that were upgraded to Tahoe from a prior macOS version, suggesting the bug may be tied to the upgrade path rather than Tahoe itself.

Environment:
- macOS: 26 Tahoe (upgraded from macOS 15 Sequoia)
- Hardware: MacBook Pro M3 Pro
- App affected: Adobe InDesign 2026 (also reported in Illustrator and Acrobat)

Notes:
This has been widely reported in Adobe's community forums since Tahoe's release in September 2025 and remains unresolved as of April 2026. Because the issue occurs across multiple Adobe apps, it appears to be a macOS-level bug in the system Save dialog rather than an app-specific issue.

I've included a screen recording of this example being exported. Note that I am NOT hitting the "delete" button. I'm hitting the space bar and then in the second attempt I'm trying to type an underscore to save another version of the file in the folder.