Steps to reproduce:

• Start NVDA
• Try to unplug/re-plug the braille display
• Try to set braille display to "No braille" and then again to "Automatic"

Actual behavior:

No braille on the display.

Expected behavior:

Braille should be refreshed on the display.

NVDA logs, crash dumps and other attachments:

nvda.log

System configuration

NVDA installed/portable/running from source:

Temporary version from launcher.

NVDA version:

nvda_snapshot_alpha-28542,8accbfa7.exe

Windows version:

Windows 10 21H2 (AMD64) build 19044.3086

Name and version of other software in use when reproducing the issue:

N/A

Other information about your system:

N/A

Other questions

Does the issue still occur after restarting your computer?

Yes

Have you tried any other versions of NVDA? If so, please report their behaviors.

• NVDA 2023.1 installed: braille OK
• nvda_snapshot_alpha-28351,ffa9d798.exe (temp version): braille OK
• nvda_snapshot_alpha-28355,02199b76.exe (temp version): braille NOK
• Another recent alpha portable: braille NOK
• nvda_snapshot_try-fix-14872-28527,83b07642.exe (coming from NVDA freeze while reloading the configuration #14872 (comment)): braille NOK
• Last alpha from source (commit 3f89b60): braille OK!
• Alpha from source (commit a0a146d): braille OK
• Alpha from source, some other commits around between April 3rd and today (June 30th): braille OK

If NVDA add-ons are disabled, is your problem still occurring?

Yes

Does the issue still occur after you run the COM Registration Fixing Tool in NVDA's tools menu?

Not tested, probably unrelated.

Investigation

To summarize various version tests:

• all tested versions running from source are running well
• on compiled versions (at least temporary and portable versions), the issue has been introduced between nvda_snapshot_alpha-28351,ffa9d798.exe and nvda_snapshot_alpha-28355,02199b76.exe.

Looking at the possible range of commits between these two alpha versions, we have the following three commits which may have introduced the issue:

• Commit 02199b7: Add-on store: add missing changelog entries
• Commit a0a146d: Eurobraille bnote and bbook automatic detection (Eurobraille bnote and bbook automatic detection #14690)
• Commit 671c8ba: Bump requests from 2.28.2 to 2.31.0 (Bump requests from 2.28.2 to 2.31.0 #14965)

Given the subject, #14690 is very likely.

Cc @FalkoBabbage:
When testing #14690, have you or Eurobraille guys also tested the older displays?