No display between Optiplex 7070 and P2219H monitor

I am connecting a refurbished (Grade A from Microsoft authorized refurbisher) Optiplex 7070 running Windows 11 via displayport and displayport-to-hdmi adapter to a P2219H monitor, but not getting a signal. The same connection to a Sharp television works fine. The cable and monitor are both fine. Since the displayport 1.2 is ++ (enabled for conversion to hdmi signal) my understanding is that it should work with the monitor hdmi 1.4 port. I've updated the integrated graphics driver, set the monitor for hdmi input, tried both displayports on the computer, and made sure the monitor was on before booting the computer.  In device manager, only the PnP generic monitor driver appears on the television, but I think that should work for the monitor . Any help would be appreciated.