Install freezes after "??? """ dialog

Distribution

Mint 22 Cinnamon

Package version

6.2.9

Graphics hardware in use

NVD9

Frequency

Always

Bug description

Trying to install Mint on a Dell Optiplex 990 which is currently running Ubuntu OK.
Mint runs OK from the bootable USB stick. I try to run install.
I get a dialog showing "??? ???" in both subject and content. I click on OK to continue. After answering whether I want extra codecs loaded, the install freezes. Saying yes or no to the codecs makes no difference.

Steps to reproduce

Attempt to Install Mint 22 on a Dell Optiplex 990 from the Mint running on it OK from a boot USB stick.

Expected behavior

I expect the install to proceed OK, and I don't expect to see a dialog with "??? ???" as its topic and text.

Additional information

The destination drive is a 256GB SSD which is currently running Ubuntu without issue.
Tried both legacy and UEFI modes. No difference. (Ubuntu runs under either.)

I'm happy to provide any diagnostics that might be useful.

No files, tests, or entry points are identified in the report. Start by reproducing the Mint 22 installation on the stated Dell Optiplex 990 configuration and collect installer diagnostics around the "??? ???" dialog and freeze; done means identifying the failure and confirming that installation proceeds without the dialog.