Date: 13 September 2026
Scope: Windows 10/11 64-bit international DCH WHQL Game Ready packages 610.88 (known good) and 616.92 (reported bad), inspected statically on macOS.
The evidence points to an R615 DisplayPort 2.x/UHBR display-stack regression, not a game profile, application, PNY board INF, or ordinary installer regression.
The highest-probability trigger is a new R615 policy which performs a display-head shutdown on more DP 2.x link-configuration transitions. In R610, shutdown was avoided whenever the candidate link's total data rate was at least the active rate. In R615, a DP 2.x connection avoids shutdown only when the whole target link configuration exactly matches the active configuration. NVIDIA added an internal compatibility switch named DP_LEGACY_HEAD_SHUTDOWN_POLICY for the old behaviour.