Fails to display on any monitor change on driver 455 and 460, reverting to 450 things work again

I originally reported this problem to the Debian package maintainers, but on trying some things and failing, the thought it it might be an upstream issue, so I’m reporting the issue here as well. Here’s a summary:

I’m having a problem that renders the nvidia driver versions 455 and 460
that have been available on Debian unusable to me. When installed, the
system usually boots up fine and appears to work until something happens
that affects the link to the monitor - this could be removing the HDMI
cable, DPMS being activated for screen blanking, or switching to a
different input on the monitor (as I have two computers connected to

At that point, when the link is restored (for example by reconnecting
the HDMI cable, moving the mouse or switching back to the HDMI input for
this computer), no sync is seen again. Examining the X logs, it appears
that the monitor is seen multiple times at this point, but never gains
sync. Switching to a VC and disconnecting and reconnecting the cable has
very occasionally restored the display, but often it doesn’t and a
reboot is required.

Switching back to version 450 as was in testing until a week or two ago,
none of these problems exist. Despite this, just in case, I’ve tried
changing the HDMI cable, and 460 still exhibits the same problems. I’ve
had to switch back to 450 to enable work to continue, as I have to
regularly switch inputs on this computer.

I’m unsure what information would be useful to progress, but I’m very
happy to provide any information requested or test any changes. Just let
me know and I’ll get back to you as soon as possible.

Bug report output from 450 (working fine) and 460 (exhibiting the problem) are attached. The files are both taken after booting, starting X, then switching the monitor to a new input, and then shortly after switching back.

For reference, the original bug report with Debian is at

nvidia-bug-report-450.log.gz (103.8 KB) nvidia-bug-report-460.log.gz (67.7 KB)